A276287 Number of ways of writing n as a sum of 15 squares.

1, 30, 420, 3640, 21870, 96936, 331240, 911040, 2128260, 4495430, 8972712, 16946280, 29822520, 49476840, 80027280, 127083328, 193511790, 282611280, 409172940, 590913960, 825736296, 1115671760, 1509537960, 2048372160, 2698852520, 3463029894

Offset

0,2

Links

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

Eric Weisstein's World of Mathematics, Sum of Squares Function

Eric Weisstein's World of Mathematics, Jacobi Theta Functions

Index entries for sequences related to sums of squares

Formula

G.f.: theta_3(0,q)^15, where theta_3(x,q) is the third Jacobi theta function.

Mathematica

Table[SquaresR[15, n], {n, 0, 28}]

Crossrefs

Cf. similar sequences of number of ways of writing n as a sum of k squares listed in A276285.

15th column of A286815.

Sequence in context: A296917 A255002 A126922 * A106440 A097213 A110612

Adjacent sequences: A276284 A276285 A276286 * A276288 A276289 A276290

Keyword

nonn,easy

Author

Ilya Gutkovskiy, Aug 27 2016

Status

approved