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Search: a063011 -id:a063011
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Ordered product of the sides of primitive Pythagorean triangles divided by 60.
+10
2
1, 13, 34, 70, 203, 246, 259, 671, 1092, 1113, 1547, 2002, 3164, 3212, 3333, 3927, 4628, 5916, 7566, 8294, 9919, 10317, 10725, 17017, 17731, 17927, 21098, 24739, 26818, 29359, 30932, 34952, 40222, 40690, 49062, 50609, 51338, 53669, 59787
OFFSET
1,2
CROSSREFS
a(n)=A063011(n)/60. Subsequence of A057097.
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Apr 08 2003
EXTENSIONS
More terms from Ray Chandler, Oct 28 2003
STATUS
approved
Hypotenuses of primitive Pythagorean triangles sorted on product of sides.
+10
2
5, 13, 17, 25, 29, 41, 37, 61, 65, 53, 85, 65, 113, 73, 101, 85, 89, 145, 97, 145, 109, 181, 125, 221, 149, 197, 137, 173, 265, 157, 185, 257, 169, 313, 185, 229, 193, 205, 365, 325, 205, 269, 233, 421, 221, 293, 241, 265, 401, 481, 317, 277, 545, 365, 485, 281
OFFSET
1,1
CROSSREFS
Cf. A063011.
Cf. A057100.
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Nov 14 2003
EXTENSIONS
More terms from Ray Chandler, Nov 16 2003
STATUS
approved
Scale factor by which primitive Pythagorean triangle {x=A088509(n), y=A088510(n), z=A088511(n)} needs be enlarged in order to circumscribe the smallest integral square having a side on the hypotenuse.
+10
2
37, 229, 409, 793, 1261, 2041, 1789, 4381, 5233, 4069, 8317, 6073, 14449, 7969, 12181, 9997, 11041, 23473, 14089, 24457, 17341, 36181, 20773, 53461, 29341, 44269, 28009, 38509, 76297, 35869, 44257, 74209, 42841, 105769, 50137, 65701, 53209
OFFSET
1,1
COMMENTS
Such an inscribed square has side x*y*z = A063011(n).
Also the radius squared of the Conway circle of a primitive Pythagorean triangle, sorted on product of sides. - Frank M Jackson, Nov 04 2023
REFERENCES
J. D. E. Konhauser et al., Which Way Did The Bicycle Go?, Problem 21, "The Square on the Hypotenuse", pp. 7; 79-80, Dolciani Math. Exp. No. 18, MAA, 1996.
LINKS
Eric W. Weisstein, MathWorld: Conway circle.
FORMULA
a(n) = x*y + z^2.
a(n) = s^2 + r^2, where s is the semiperimeter and r is the inradius of triangle (x, y, z).
MATHEMATICA
lst={}; k=25; Do[If[GCD[m, n]==1&&OddQ[m+n], AppendTo[lst, {2m*n(m^4-n^4), m^2(m+n)^2+n^2(m-n)^2}]], {m, 1, k}, {n, 1, m}]; lst=Sort@lst; Table[lst[[n]][[2]], {n, 1, 100}] (* Frank M Jackson, Nov 04 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Nov 17 2003
EXTENSIONS
More terms from Max Alekseyev, May 30 2009
STATUS
approved
Short leg of primitive Pythagorean triangles sorted on product of sides.
+10
1
3, 5, 8, 7, 20, 9, 12, 11, 16, 28, 13, 33, 15, 48, 20, 36, 39, 17, 65, 24, 60, 19, 44, 21, 51, 28, 88, 52, 23, 85, 57, 32, 119, 25, 104, 60, 95, 84, 27, 36, 133, 69, 105, 29, 140, 68, 120, 96, 40, 31, 75, 115, 33, 76, 44, 160, 161, 136, 35, 207, 87, 48, 84, 204, 175, 37
OFFSET
1,1
CROSSREFS
Cf. A063011.
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Nov 14 2003
EXTENSIONS
More terms from Ray Chandler, Nov 16 2003
STATUS
approved
Long leg of primitive Pythagorean triangles sorted on product of sides.
+10
1
4, 12, 15, 24, 21, 40, 35, 60, 63, 45, 84, 56, 112, 55, 99, 77, 80, 144, 72, 143, 91, 180, 117, 220, 140, 195, 105, 165, 264, 132, 176, 255, 120, 312, 153, 221, 168, 187, 364, 323, 156, 260, 208, 420, 171, 285, 209, 247, 399, 480, 308, 252, 544, 357, 483, 231
OFFSET
1,1
CROSSREFS
Cf. A063011.
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Nov 14 2003
EXTENSIONS
More terms from Ray Chandler, Nov 16 2003
STATUS
approved
Ordered product of the terms in a primitive Pythagorean quadruple (with repetitions).
+10
1
12, 252, 288, 1008, 1188, 1872, 2052, 2100, 2448, 2772, 3300, 8400, 8448, 9108, 9828, 11628, 12768, 13500, 14688, 17100, 17388, 17388, 17472, 18900, 25500, 27900, 29568, 29568, 31968, 32292, 32508, 33408, 50388, 51612, 54000, 58212, 58812, 60372, 62100, 62832, 63072, 65472, 65892, 69300, 69972
OFFSET
1,1
COMMENTS
Every primitive Pythagorean quadruple (PPQ) generates a distinct Heronian triangle. This sequence is the area of such a triangle. If a, b, c, d form a PPQ where a^2 + b^2 + c^2 = d^2 it generates a primitive Heronian triangle whose three sides are b^2 + c^2, a^2 + c^2, a^2 + b^2. Its semiperimeter is d^2 and its area is a*b*c*d. It has an inradius and three exradii as a*b*c/d, b*c*d/a, a*c*d/b, a*b*d/c respectively.
a(n) == 0 mod 12.
A210484 is a subsequence because an integer Soddyian triangle has area m^2n^2(m+n)^2(m^2+mn+n^2) and semiperimeter (m^2+mn+n^2)^2 = m^2*n^2 + n^2(m+n)^2 + m^2(m+n)^2 where m >= n and GCD(m,n) = 1. This is a PPQ.
LINKS
Eric Weisstein's World of Mathematics, Pythagorean Quadruple.
EXAMPLE
a(5)=1188 because the 5th occurrence of a PPQ sorted by the product of its term is (2, 6, 9, 11) and 1188 = 11*9*6*2.
MATHEMATICA
lst = {}; Do[lst=Join[lst, Select[PowersRepresentations[k^2, 3, 2], Times@@#!=0&&GCD@@#==1 &]], {k, 1, 100}]; lst1=Sort@(Table[{a, b, c}=lst[[n]]; a*b*c*Sqrt[a^2+b^2+c^2], {n, 1, Length@lst}]); lst1[[1;; 50]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Frank M Jackson, Nov 28 2023
STATUS
approved
Ordered products of the perimeter and the sides of primitive Pythagorean triangles.
+10
0
720, 23400, 81600, 235200, 852600, 1305360, 1328400, 5314320, 8414280, 9434880, 16893240, 18498480, 33918720, 43995600, 45561600, 46652760, 57757440, 106226640, 108617760, 154736400, 155263680, 184041000, 235227600, 361712400, 417740400, 451760400, 471711240
OFFSET
1,1
COMMENTS
Considering the set of primitive Pythagorean triangles with sides (A, B, C), the sequence gives the values (A+B+C)*(A*B*C), in increasing order.
It is a challenge to find a pair of primitive Pythagorean triangles such that product of perimeter and the sides is equal.
EXAMPLE
a(1) = (3+4+5)*(3*4*5) = 720.
a(2) = (5+12+13)*(5*12*13) = 23400.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mihir Mathur, Apr 02 2013
EXTENSIONS
Corrected and extended by Giovanni Resta, Apr 03 2013
STATUS
approved

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