A055405 - OEIS

A055405

Number of points in N^6 of norm <= n.

1, 7, 63, 337, 1319, 3819, 9763, 21374, 43774, 81586, 145138, 243345, 394696, 612274, 928616, 1363401, 1967428, 2762729, 3825273, 5197436, 6974412, 9198648, 12019669, 15500750, 19827441, 25050955, 31438147, 39053729, 48254762

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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))^6/(64*(1 - x)), where theta_3() is the Jacobi theta function. - Ilya Gutkovskiy, Apr 15 2018

CROSSREFS

Column k=6 of A302998.

Sequence in context: A007291 A343137 A188226 * A100741 A043027 A165759

Adjacent sequences: A055402 A055403 A055404 * A055406 A055407 A055408

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved