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A014805 Expansion of Jacobi theta constant (theta_2/2)^16. 2
1, 16, 120, 576, 2060, 6048, 15424, 35200, 73518, 143280, 263584, 461376, 775160, 1256928, 1973760, 3017088, 4503557, 6572880, 9411984, 13249280, 18340932, 25034976, 33739520, 44879616, 59057510, 76949920, 99212352, 126838080, 160884264, 202296960, 252645376 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Number of ways of writing n as the sum of 16 triangular numbers from A000217. - Seiichi Manyama, May 05 2017

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..10000

J. G. Huard and K. S. Williams, Sums of sixteen and twenty-four triangular numbers, Rocky Mountain J. Math. Volume 35, Number 3 (2005), 857-868.

FORMULA

a(n) = 1/192 * Sum_{a, b, x, y > 0, a*x + b*y = 2*n + 4, a == b == x == y == 1 mod 2 and a > b} a*b*(a^2 - b^2)^2. - Seiichi Manyama, May 05 2017

a(0) = 1, a(n) = (16/n)*Sum_{k=1..n} A002129(k)*a(n-k) for n > 0. - Seiichi Manyama, May 06 2017

CROSSREFS

Column k=16 of A286180.

Sequence in context: A138571 A047641 A010932 * A022611 A324066 A164542

Adjacent sequences:  A014802 A014803 A014804 * A014806 A014807 A014808

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Seiichi Manyama, May 05 2017

STATUS

approved

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Last modified October 22 07:48 EDT 2019. Contains 328315 sequences. (Running on oeis4.)