A055406 - OEIS

A055406

Number of points in N^7 of norm <= n.

1, 8, 106, 702, 3390, 11496, 33792, 83877, 191433, 394251, 766518, 1397065, 2446316, 4076126, 6601783, 10324698, 15776495, 23436651, 34198045, 48828417, 68680634, 94868383, 129404333, 173984393, 231540046, 304058667, 395837165

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OFFSET

0,2

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..500

FORMULA

a(n) = [x^(n^2)] (1 + theta_3(x))^7/(128*(1 - x)), where theta_3() is the Jacobi theta function. - Ilya Gutkovskiy, Apr 15 2018

CROSSREFS

Column k=7 of A302998.

Sequence in context: A113551 A082735 A024358 * A155632 A129278 A369512

Adjacent sequences: A055403 A055404 A055405 * A055407 A055408 A055409

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved