Displaying 1-10 of 11 results found.
Primes of the form k^16 + (k+1)^16.
+10
14
65537, 4338014017, 2973697798081, 36054040477057, 314707907280257, 8746361693522261761, 4441930186581050471617, 1936348941361814438534657, 8260002645666200230661441, 157512780598351804823277697, 684655198104511486296198721, 21770695412796292350304592257
COMMENTS
Prime 16-dimensional centered cube numbers. This is to dimension 16 as A194155 is to dimension 8 and as A152913 is to dimension 4.
EXAMPLE
a(1) = 1^16 + (1+1)^16 = 65537 = A100266(2). a(2) = 3^16 + (3+1)^16 = 4338014017 = A100266(3). a(3) = 5^16 + (5+1)^16 = 2973697798081 = A100266(4). a(4) = 6^16 + (6+1)^16 = 36054040477057 = A100266(5). a(5) = 7^16 + (7+1)^16 = 314707907280257 = A100266(6). a(6) = 14^16 + (14+1)^16 = 8746361693522261761 = A100266(11). a(7) = 21^16 + (21+1)^16 = 4441930186581050471617 = A100266(22).
MATHEMATICA
Select[Table[n^16+(n+1)^16, {n, 0, 800}], PrimeQ] (* Vincenzo Librandi, Dec 07 2011 *) Select[Total/@Partition[Range[60]^16, 2, 1], PrimeQ] (* Harvey P. Dale, Dec 07 2017 *)
PROG
(Magma) [ a: n in [1..100] | IsPrime(a) where a is n^16+(n+1)^16 ]; // Vincenzo Librandi, Dec 07 2011
Primes of the form k^32 + (k+1)^32.
+10
10
3512911982806776822251393039617, 2211377674535255285545615254209921, 476961452964007550415682034114910337, 46677208572152524490331633250547044320123137
COMMENTS
Prime 32-dimensional centered cube numbers. This is to dimension 32 as A194185 is to dimension 16; as A194155 is to dimension 8; and as A152913 is to dimension 4.
EXAMPLE
a(1) = 8^32 + (8 + 1)^32 = A100267(2). a(3) = 12^32 + (12 + 1)^32 = A100267(4). a(4) = 22^32 + (22 + 1)^32.
MATHEMATICA
Select[Table[n^32+(n+1)^32, {n, 1, 3000}], PrimeQ] (* Vincenzo Librandi, Dec 08 2011 *)
PROG
(Magma) [a: n in [1..200] | IsPrime(a) where a is n^32+(n+1)^32]; // Vincenzo Librandi, Dec 08 2011
Centered cube numbers: (n+1)^7 + n^7.
+10
9
1, 129, 2315, 18571, 94509, 358061, 1103479, 2920695, 6880121, 14782969, 29487171, 55318979, 98580325, 168162021, 276272879, 439294831, 678774129, 1022558705, 1506091771, 2173871739, 3081088541, 4295446429, 5899183335, 7991296871, 10689987049, 14135325801
COMMENTS
Never prime, as a(n) = (2n+1)*(n^6 + 3n^5 + 9n^4 + 13n^3 + 11n^2 + 5n + 1). Semiprimes in the sequence begin for n = 1, 2, 8, 9, 21, 30, 33, 53, 65, 81, 83. - Jonathan Vos Post, Aug 26 2011
REFERENCES
B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.
FORMULA
G.f.: (1+x)*(x^6 + 120*x^5 + 1191*x^4 + 2416*x^3 + 1191*x^2 + 120*x + 1) / (x-1)^8. - R. J. Mathar, Aug 27 2011
Centered cube numbers: a(n) = (n+1)^9 + n^9.
+10
7
1, 513, 20195, 281827, 2215269, 12030821, 50431303, 174571335, 521638217, 1387420489, 3357947691, 7517728043, 15764279725, 31265546157, 59104406159, 107162836111, 187307353233, 316947166865
COMMENTS
Never prime nor semiprime, as a(n) = (2n+1) * (n^2 + n + 1) * (n^6 + 3n^5 + 12n^4 + 19n^3 + 15n^2 + 6n + 1). - Jonathan Vos Post, Aug 26 2011
REFERENCES
B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.
LINKS
Index entries for linear recurrences with constant coefficients, signature (10, -45, 120, -210, 252, -210, 120, -45, 10, -1).
FORMULA
G.f.: (1+x)*(x^8 + 502*x^7 + 14608*x^6 + 88234*x^5 + 156190*x^4 + 88234*x^3 + 14608*x^2 + 502*x + 1) / (x-1)^10. - R. J. Mathar, Aug 27 2011
MATHEMATICA
Total/@Partition[Range[0, 20]^9, 2, 1] (* Harvey P. Dale, Jan 31 2015 *) LinearRecurrence[{10, -45, 120, -210, 252, -210, 120, -45, 10, -1}, {1, 513, 20195, 281827, 2215269, 12030821, 50431303, 174571335, 521638217, 1387420489}, 20] (* Harvey P. Dale, Jan 21 2023 *)
Centered cube numbers: (n+1)^10 + n^10.
+10
6
1, 1025, 60073, 1107625, 10814201, 70231801, 342941425, 1356217073, 4560526225, 13486784401, 35937424601, 87854788825, 199775856073, 427113146825, 865905045601, 1676162018401, 3115505528225
COMMENTS
Never prime, as a(n) = (2n^2 + 2n + 1) * (n^8 + 4n^7 + 18n^6 + 40n^5 + 56n^4 + 50n^3 + 27n^2 + 8n + 1), multiple of A001844(n). Semiprime for n in {2, 4, 7, 14, 19, 22, 32, 60, 65, 70, 87, 99, 102, 135, 137, ...}. - Jonathan Vos Post, Aug 26 2011
REFERENCES
B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.
FORMULA
G.f.: -(x^8 + 1012*x^7 + 46828*x^6 + 408364*x^5 + 901990*x^4 + 408364*x^3 + 46828*x^2 + 1012*x + 1)*(1+x)^2 / (x-1)^11. - R. J. Mathar, Aug 27 2011
MATHEMATICA
Total/@Partition[Range[0, 20]^10, 2, 1] (* Harvey P. Dale, Aug 04 2019 *)
Centered cube numbers: (n+1)^11 + n^11.
+10
5
1, 2049, 179195, 4371451, 53022429, 411625181, 2340123799, 10567261335, 39970994201, 131381059609, 385311670611, 1028320041299, 2535168764725, 5841725563701, 12699321029039, 26241941903791, 51864082352049
COMMENTS
Never prime, as a(n) = (2*n+1) * (n^10 + 5*n^9 + 25*n^8 + 70*n^7 + 130*n^6 + 166*n^5 + 148*n^4 + 91*n^3 + 37*n^2 + 9*n + 1). - Jonathan Vos Post, Aug 26 2011
LINKS
Index entries for linear recurrences with constant coefficients, signature (12,-66,220,-495,792,-924,792,-495,220,-66,12,-1).
FORMULA
G.f.: (1 + x)*(1 + 2036*x + 152637*x^2 + 2203488*x^3 + 9738114*x^4 + 15724248*x^5 + 9738114*x^6 + 2203488*x^7 + 152637*x^8 + 2036*x^9 + x^10) / (1 - x)^12.
a(n) = 12*a(n-1) - 66*a(n-2) + 220*a(n-3) - 495*a(n-4) + 792*a(n-5) - 924*a(n-6) + 792*a(n-7) - 495*a(n-8) + 220*a(n-9) - 66*a(n-10) + 12*a(n-11) - a(n-12) for n>11.
(End)
PROG
(PARI) Vec((1 + x)*(1 + 2036*x + 152637*x^2 + 2203488*x^3 + 9738114*x^4 + 15724248*x^5 + 9738114*x^6 + 2203488*x^7 + 152637*x^8 + 2036*x^9 + x^10) / (1 - x)^12 + O(x^40)) \\ Colin Barker, Feb 06 2020
Centered cube numbers: (n+1)^12 + n^12.
+10
4
1, 4097, 535537, 17308657, 260917841, 2420922961, 16018069537, 82560763937, 351149013217, 1282429536481, 4138428376721, 12054528824977, 32214185570737, 79991997497777, 186440250265921, 411221314601281
COMMENTS
Never prime, as a(n) = (2n^4 + 4n^3 + 6n^2 + 4n + 1) * (n^8 + 4n^7 + 22n^6 + 52n^5 + 69n^4 + 56n^3 + 28n^2 + 8n + 1) Semiprime for n in {1, 2, 3, 6, 14, 16, 36, 87, 97, 109, 110, 119, 121, 163, 195, ...}. - Jonathan Vos Post, Aug 26 2011
REFERENCES
B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.
FORMULA
G.f.: -(x^10 + 4082*x^9 + 474189*x^8 + 9713496*x^7 + 56604978*x^6 + 105907308*x^5 + 56604978*x^4 + 9713496*x^3 + 474189*x^2 + 4082*x + 1)*(1+x)^2 / (x-1)^13. - R. J. Mathar, Aug 27 2011
MATHEMATICA
Total/@Partition[Range[0, 20]^12, 2, 1] (* Harvey P. Dale, May 09 2018 *)
Centered cube numbers: a(n) = (n+1)^14 + n^14.
+10
3
1, 16385, 4799353, 273218425, 6371951081, 84467679721, 756587236945, 5076269583953, 27274838966065, 122876792454961, 479749833583241, 1663668298132105, 5221294850248153, 15049383211257305, 40304932850948641, 101250520063318561, 240435420597328865
COMMENTS
Never prime, as a(n) = (2n^2 + 2n + 1) * (n^12 + 6n^11 + 39n^10 + 140n^9 + 341n^8 + 590n^7 + 741n^6 + 680n^5 + 451n^4 + 210n^3 + 65n^2 + 12n + 1). Semiprime for n in {2, 5, 22, 24, 34, 35, 39, 84, 217, 220, 285, ...}. - Jonathan Vos Post, Aug 26 2011
LINKS
Index entries for linear recurrences with constant coefficients, signature (15,-105,455,-1365,3003,-5005,6435,-6435,5005,-3003,1365,-455,105,-15,1).
FORMULA
G.f.: -(x +1)^2*(x^12 +16368*x^11 +4520946*x^10 +193889840*x^9 +2377852335*x^8 +10465410528*x^7 +17505765564*x^6 +10465410528*x^5 +2377852335*x^4 +193889840*x^3 +4520946*x^2 +16368*x +1) / (x -1)^15. - Colin Barker, Feb 16 2015
CROSSREFS
Cf. A000040, A036085, A036087, A036088, A036089, A036090, A036091, A100267, A154535, A100266, A152913, A194155, A194185, A194216.
Centered cube numbers: (n+1)^25 + n^25.
+10
3
1, 33554433, 847322163875, 1126747195452067, 299149123783795749, 28728311253806654501, 1369498907693894602183, 39120000482621126610375, 755676919554809750479817, 10717897987691852588770249, 118347059433883722041830251
COMMENTS
Can never be prime as a(n) = (2*n+1) * (n^4 + 2*n^3 + 4*n^2 + 3*n+1) * (n^20 + 10*n^19 + 120*n^18 + 795*n^17 + 3685*n^16 + 12752*n^15 + 33965*n^14 + 71205*n^13 + 119580*n^12 + 162965*n^11 + 181754*n^10 + 166595*n^9 + 125515*n^8 +77415*n^7 + 38745*n^6 + 15503*n^5 + 4845*n^4 + 1140*n^3 + 190*n^2 + 20*n + 1).
LINKS
Index entries for linear recurrences with constant coefficients, signature (26, -325, 2600, -14950, 65780, -230230, 657800, -1562275, 3124550, -5311735, 7726160, -9657700, 10400600, -9657700, 7726160, -5311735, 3124550, -1562275, 657800, -230230, 65780, -14950, 2600, -325, 26, -1).
MATHEMATICA
Total/@Partition[Range[0, 20]^25, 2, 1] (* Harvey P. Dale, Dec 03 2015 *)
Centered cube numbers: a(n) = (n+1)^17 + n^17.
+10
2
1, 131073, 129271235, 17309009347, 780119322309, 17689598897861, 249557173431943, 2484430327672455, 18928981513351817, 116677181699666569, 605447028499293771, 2724058135239730763, 10869027026121774925
COMMENTS
Never prime, as a(n) = (2n + 1) * (n^16 + 8n^15 + 64n^14 + 308n^13 + 1036n^12 + 2576n^11 + 4900n^10 + 7274n^9 + 8518n^8 + 7896n^7 + 5776n^6 + 3300n^5 + 1444n^4 + 468n^3 + 106n^2 + 15n + 1). Semiprime for n in {1, 5, 21, 29, 33, ...}. - Jonathan Vos Post, Aug 27 2011
REFERENCES
B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.
CROSSREFS
Cf. A000040, A036085, A036087, A036088, A036089, A036090, A036091, A036092, A036093, A100267, A154535, A100266, A152913, A194155, A194185, A194216.
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