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Search: a093732 -id:a093732
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a(n) = 7^n - 3*4^n + 2*3^n.
(Formerly M5078 N2197)
+10
17
1, 19, 205, 1795, 14221, 106819, 778765, 5581315, 39606541, 279447619, 1965098125, 13792018435, 96690872461, 677427332419, 4744368982285, 33220131761155, 232579232659981, 1628208214321219, 11398072876175245, 79788974736297475, 558532690864457101
OFFSET
1,2
COMMENTS
Counts connected relations. On page 578 Kreweras (1969) says: "Le théorème s'applique notamment au dénombrement des relations binaires externes qui possèdent la propriété de connexité; cela revient à calculer le nombre a(m,n) de manières de remplir un tableau de m lignes et n colonnes avec des 0 et des 1, en respectant les deux conditions suivantes: (1): aucune rangée (ligne ni colonne) ne doit être tout entière remplie de zéros; (2): deux cases quelconques marquées 1 peuvent être jointes par une chaîne de cases marquées 1 telle que deux cases consécutives de la chaîne appartiennent à une même rangée."
REFERENCES
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
FORMULA
G.f.: -x*(1+5*x) / ( (3*x-1)*(7*x-1)*(4*x-1) ). - R. J. Mathar, Jun 09 2013
a(n) = 14*a(n-1) - 61*a(n-2) + 84*a(n-3). - Wesley Ivan Hurt, Apr 11 2022
MATHEMATICA
Table[7^n - 3*4^n + 2*3^n, {n, 20}] (* T. D. Noe, May 29 2012 *)
PROG
(PARI) a(n)=7^n-3*4^n+2*3^n \\ Charles R Greathouse IV, Sep 24 2015
CROSSREFS
A diagonal of A262307.
KEYWORD
nonn,easy
EXTENSIONS
Better definition and more terms from Goran Kilibarda, Vladeta Jovovic, Apr 14 2004
STATUS
approved
Number of connected relations.
(Formerly M5336 N2323)
+10
17
1, 65, 1795, 36317, 636331, 10365005, 162470155, 2495037197, 37898120011, 572284920845, 8614868501515, 129467758660877, 1943971108806091, 29175170378428685, 437752102106036875, 6567275797761209357
OFFSET
1,2
REFERENCES
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
FORMULA
15^n-4*8^n-3*6^n+12*5^n-6*4^n. - Goran Kilibarda, Vladeta Jovovic, Apr 14 2004
G.f. x*( -1-27*x+136*x^2+480*x^3 ) / ( (6*x-1)*(5*x-1)*(15*x-1)*(4*x-1)*(8*x-1) ).
- R. J. Mathar, Jun 09 2013
MATHEMATICA
LinearRecurrence[{38, -539, 3622, -11640, 14400}, {1, 65, 1795, 36317, 636331}, 20] (* Harvey P. Dale, Mar 24 2017 *)
CROSSREFS
A diagonal of A262307.
KEYWORD
nonn,nice,easy
EXTENSIONS
More terms from Goran Kilibarda, Vladeta Jovovic, Apr 14 2004
STATUS
approved
Number of connected relations.
+10
13
1, 665, 106819, 10365005, 805351531, 56294206205, 3735873535339, 241600284318365, 15423235216318411, 978180744322139645, 61834480769377286059, 3902270609960140639325, 246057483524862034206091, 15508484277325946034039485, 977254123876968508188975979
OFFSET
1,2
LINKS
Goran Kilibarda and Vladeta Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.
Index entries for linear recurrences with constant coefficients, signature (-195, 15886, -726290, 20952193, -403792115, 5336718048, -48588590600, 299693200656, -1195947048240, 2785165036416, -2872859996160).
FORMULA
a(n) = 63^n - 6*32^n - 15*18^n + 30*17^n - 10*14^n + 120*11^n - 120*10^n + 30*9^n - 270*8^n + 360*7^n - 120*6^n.
G.f.: x*(96368590080*x^9 + 27682953984*x^8 - 13185435000*x^7 + 774468980*x^6 + 143028190*x^5 - 19071533*x^4 + 626800*x^3 + 6970*x^2 - 470*x - 1) / ((6*x -1)*(7*x -1)*(8*x -1)*(9*x -1)*(10*x -1)*(11*x -1)*(14*x -1)*(17*x -1)*(18*x -1)*(32*x -1)*(63*x -1)). - Colin Barker, Jul 07 2013
MATHEMATICA
Table[63^n-6*32^n-15*18^n+30*17^n-10*14^n+120*11^n-120*10^n+30*9^n-270*8^n+360*7^n-120*6^n, {n, 1, 25}] (* G. C. Greubel, Oct 06 2017 *)
CoefficientList[Series[x (96368590080x^9+27682953984x^8-13185435000x^7+774468980x^6+ 143028190x^5-19071533x^4+626800x^3+6970x^2-470x-1)/((6x-1)(7x-1)(8x-1)(9x-1)(10x-1)(11x-1)(14x-1)(17x-1)(18x-1)(32x-1)(63x-1)), {x, 0, 20}], x] (* or *) LinearRecurrence[{195, -15886, 726290, -20952193, 403792115, -5336718048, 48588590600, -299693200656, 1195947048240, -2785165036416, 2872859996160}, {0, 1, 665, 106819, 10365005, 805351531, 56294206205, 3735873535339, 241600284318365, 15423235216318411, 978180744322139645}, 20] (* Harvey P. Dale, Sep 23 2023 *)
PROG
(PARI) for(n=1, 25, print1(63^n-6*32^n-15*18^n+30*17^n-10*14^n+120*11^n-120*10^n+30*9^n-270*8^n+360*7^n-120*6^n, ", ")) \\ G. C. Greubel, Oct 06 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Goran Kilibarda and Vladeta Jovovic, Apr 14 2004
STATUS
approved
Number of connected (4,n)-hypergraphs (without empty edges).
+10
6
0, 1, 10, 135, 1992, 30166, 458885, 6965225, 105358102, 1588998756, 23915093535, 359444209015, 5397938190512, 81022969645346, 1215801458118985, 18240857019892005, 273644796626023722, 4104936328561231936
OFFSET
0,3
LINKS
Goran Kilibarda and Vladeta Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.
FORMULA
E.g.f.: (1/4!)*(exp(15*x) - 4*exp(8*x) + 6*exp(7*x) - 3*exp(6*x) + 12*exp(5*x) - 24*exp(4*x) + 23*exp(3*x) - 11*exp(2*x) + 6*exp(x) - 6).
MATHEMATICA
With[{nmax = 50}, CoefficientList[Series[(1/4!)*(Exp[15*x] - 4*Exp[8*x] + 6*Exp[7*x] - 3*Exp[6*x] + 12*Exp[5*x] - 24*Exp[4*x] + 23*Exp[3*x] - 11*Exp[2*x] + 6*Exp[x] - 6), {x, 0, nmax}], x] Range[0, nmax]!] (* G. C. Greubel, Oct 07 2017 *)
PROG
(PARI) x='x+O('x^50); concat([0], Vec(serlaplace((1/4!)*(exp(15*x) - 4*exp(8*x) + 6*exp(7*x) - 3*exp(6*x) + 12*exp(5*x) - 24*exp(4*x) + 23*exp(3*x) - 11*exp(2*x) + 6*exp(x) - 6)))) \\ G. C. Greubel, Oct 07 2017
KEYWORD
easy,nonn
AUTHOR
Goran Kilibarda and Vladeta Jovovic, Jan 08 2006
STATUS
approved
Number of connected (3,n)-hypergraphs (without empty edges).
+10
5
0, 1, 6, 44, 332, 2476, 18136, 130824, 933372, 6610676, 46603616, 327603904, 2298933412, 16115938476, 112906938696, 790735321784, 5536710117452, 38763269947876, 271368229299376, 1899679393564464, 13298164198917492
OFFSET
0,3
LINKS
Goran Kilibarda and Vladeta Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.
FORMULA
E.g.f.: (1/3!)*(exp(7*x) -3*exp(4*x) +5*exp(3*x) -3*exp(2*x) +2*exp(x) - 2).
MATHEMATICA
With[{nmax = 50}, CoefficientList[Series[(1/3!)*(Exp[7*x] - 3*Exp[4*x] + 5*Exp[3*x] - 3*Exp[2*x] + 2*Exp[x] - 2), {x, 0, nmax}], x] Range[0, nmax]!] (* G. C. Greubel, Oct 07 2017 *)
PROG
(PARI) x='x+O('x^50); concat([0], Vec(serlaplace((1/3!)*(exp(7*x) -3*exp(4*x) +5*exp(3*x) -3*exp(2*x) +2*exp(x) - 2)))) \\ G. C. Greubel, Oct 07 2017
KEYWORD
easy,nonn
AUTHOR
Goran Kilibarda and Vladeta Jovovic, Jan 08 2006
STATUS
approved
Number of connected (5,n)-hypergraphs (without empty edges).
+10
5
0, 1, 15, 336, 8880, 254596, 7606446, 231899522, 7137539256, 220623286632, 6831984816402, 211719998195278, 6562887569336652, 203453536535818388, 6307290799931347878, 195532244201392935354, 6061637498660735815968
OFFSET
0,3
LINKS
Goran Kilibarda and Vladeta Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.
FORMULA
E.g.f.: (1/5!)*(exp(31*x) - 5*exp(16*x) + 10*exp(15*x) - 10*exp(10*x) + 20*exp(9*x) - 40*exp(8*x) + 65*exp(7*x) - 90*exp(6*x) + 144*exp(5*x) - 165*exp(4*x) + 120*exp(3*x) - 50*exp(2*x) + 24*exp(x) - 24).
KEYWORD
easy,nonn
AUTHOR
Goran Kilibarda and Vladeta Jovovic, Jan 08 2006
STATUS
approved
Number of connected (5,n)-hypergraphs (without empty edges and without multiple edges).
+10
4
0, 0, 0, 21, 2773, 148365, 5878391, 204819447, 6721694469, 214306917321, 6736603947907, 210284186632443, 6541309609120385, 203129541349695597, 6302428271530970943, 195459285517696665759, 6060542952694406463421
OFFSET
0,4
LINKS
Goran Kilibarda and Vladeta Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.
FORMULA
E.g.f.: (1/5!)*(exp(31*x) - 5*exp(16*x) - 10*exp(15*x) - 10*exp(10*x) + 20*exp(9*x) + 40*exp(8*x) + 65*exp(7*x) - 30*exp(6*x) - 96*exp(5*x) - 45*exp(4*x) + 20*exp(3*x) + 50*exp(2*x) + 24*exp(x) - 24).
MATHEMATICA
With[{nmax = 50}, CoefficientList[Series[(1/5!)*(Exp[31*x] - 5*Exp[16*x] - 10*Exp[15*x] - 10*Exp[10*x] + 20*Exp[9*x] + 40*Exp[8*x] + 65*Exp[7*x] - 30*Exp[6*x] - 96*Exp[5*x] - 45*Exp[4*x] + 20*Exp[3*x] + 50*Exp[2*x] + 24*Exp[x] - 24), {x, 0, nmax}], x] Range[0, nmax]!] (* G. C. Greubel, Oct 07 2017 *)
PROG
(PARI) x='x+O('x^50); concat([0, 0, 0], Vec(serlaplace((1/5!)*(exp(31*x) - 5*exp(16*x) - 10*exp(15*x) - 10*exp(10*x) + 20*exp(9*x) + 40*exp(8*x) + 65*exp(7*x) - 30*exp(6*x) - 96*exp(5*x) - 45*exp(4*x) + 20*exp(3*x) + 50*exp(2*x) + 24*exp(x) - 24)))) \\ G. C. Greubel, Oct 07 2017
KEYWORD
easy,nonn
AUTHOR
Goran Kilibarda and Vladeta Jovovic, Jan 08 2006
STATUS
approved
Number of connected (4,n)-hypergraphs (without empty edges and without multiple edges).
+10
3
0, 0, 0, 32, 1094, 23055, 405475, 6575842, 102567444, 1569195485, 23775369725, 358461659952, 5391042181294, 80974624209115, 1215462744452775, 18238484835400862, 273628186560143144, 4104820038944901945
OFFSET
0,4
LINKS
Goran Kilibarda and Vladeta Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.
FORMULA
E.g.f.: (1/4!)*(exp(15*x) - 4*exp(8*x) - 6*exp(7*x) - 3*exp(6*x) + 12*exp(5*x) + 12*exp(4*x) - exp(3*x) - 11*exp(2*x) - 6*exp(x) + 6).
MATHEMATICA
With[{nmax = 50}, CoefficientList[Series[(1/4!)*(Exp[15*x] - 4*Exp[8*x] - 6*Exp[7*x] - 3*Exp[6*x] + 12*Exp[5*x] + 12*Exp[4*x] - Exp[3*x] - 11*Exp[2*x] - 6*Exp[x] + 6), {x, 0, nmax}], x] Range[0, nmax]!] (* G. C. Greubel, Oct 07 2017 *)
PROG
(PARI) x='x+O('x^50); concat([0, 0, 0], Vec(serlaplace((1/4!)*(exp(15*x)-4*exp(8*x)-6*exp(7*x)-3*exp(6*x)+12*exp(5*x)+12*exp(4*x)-exp(3*x)-11*exp(2*x)-6*exp(x)+6)))) \\ G. C. Greubel, Oct 07 2017
KEYWORD
easy,nonn
AUTHOR
Goran Kilibarda and Vladeta Jovovic, Jan 08 2006
STATUS
approved
T(n,k)=Number of nXk 0..4 arrays of sums of 2X2 subblocks of some (n+1)X(k+1) binary array
+10
3
5, 19, 19, 65, 205, 65, 211, 1795, 1795, 211, 665, 14221, 36317, 14221, 665, 2059, 106819, 636331, 636331, 106819, 2059, 6305, 778765, 10365005, 23679901, 10365005, 778765, 6305, 19171, 5581315, 162470155, 805351531, 805351531, 162470155
OFFSET
1,1
COMMENTS
Table starts
......5.........19...........65............211.............665............2059
.....19........205.........1795..........14221..........106819..........778765
.....65.......1795........36317.........636331........10365005.......162470155
....211......14221.......636331.......23679901.......805351531.....26175881341
....665.....106819.....10365005......805351531.....56294206205...3735873535339
...2059.....778765....162470155....26175881341...3735873535339.502757743028605
...6305....5581315...2495037197...831358677451.241600284318365
..19171...39606541..37898120011.26094426008221
..58025..279447619.572284920845
.175099.1965098125
.527345
LINKS
EXAMPLE
Some solutions for n=3 k=4
..1..1..1..0....0..1..1..1....0..1..1..0....1..0..1..1....1..0..2..3
..3..1..1..2....1..1..2..1....1..2..2..2....1..2..3..2....1..2..2..1
..3..2..2..3....3..1..2..3....2..1..2..3....2..3..2..1....3..3..1..0
CROSSREFS
Diagonal is A005333(n+1)
Staircase diagonal is A123281(n-3)
Column 1 is A001047(n+1)
Column 2 is A002501(n+1)
Column 3 is A002502(n+1)
Column 4 is A093732(n+1)
Column 5 is A093733(n+1)
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin Jun 14 2013
STATUS
approved
Number of connected (3,n)-hypergraphs (without empty edges and without multiple edges).
+10
2
0, 0, 1, 25, 267, 2265, 17471, 128765, 927067, 6591505, 46545591, 327428805, 2298406067, 16114352345, 112902172111, 790721005645, 5536667136267, 38763140938785, 271367842141031, 1899678231827285, 13298160713181667
OFFSET
0,4
LINKS
Goran Kilibarda and Vladeta Jovovic, Enumeration of some classes of T_0-hypergraphs, arXiv:1411.4187 [math.CO], 2014.
FORMULA
E.g.f.: (1/3!)*(exp(7*x)-3*exp(4*x)-exp(3*x)+3*exp(2*x)+2*exp(x)-2).
MATHEMATICA
With[{nmax = 50}, CoefficientList[Series[(1/3!)*(Exp[7*x] - 3*Exp[4*x] - Exp[3*x] + 3*Exp[2*x] + 2*Exp[x] - 2), {x, 0, nmax}], x] Range[0, nmax]!] (* G. C. Greubel, Oct 07 2017 *)
PROG
(PARI) x='x+O('x^50); concat([0, 0], Vec(serlaplace((1/3!)*(exp(7*x)-3*exp(4*x)-exp(3*x)+3*exp(2*x)+2*exp(x)-2)))) \\ G. C. Greubel, Oct 07 2017
KEYWORD
easy,nonn
AUTHOR
Goran Kilibarda and Vladeta Jovovic, Jan 08 2006
STATUS
approved

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