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

Author

Ilya Gutkovskiy, Aug 27 2016

Keywords

• nonn
• easy

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

Crossrefs

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

15th column of A286815.

Programs

Mathematica

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

Formula

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