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A276287
Number of ways of writing n as a sum of 15 squares.
4
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
Eric Weisstein's World of Mathematics, Sum of Squares Function
Eric Weisstein's World of Mathematics, Jacobi Theta Functions
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
KEYWORD
nonn,easy
AUTHOR
Ilya Gutkovskiy, Aug 27 2016
STATUS
approved