A055415 Number of points in Z^9 of norm <= n.

1, 19, 2869, 84663, 995241, 7129227, 35372141, 140246303, 458690081, 1318315075, 3375505573, 7945596055, 17282877369, 35516896155, 68960061837, 128236319951, 228701936081, 394678200083, 658850300869, 1072056316615

Offset: 0

Author

David W. Wilson

Keywords

• nonn

Links

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

Crossrefs

Column k=9 of A302997.

Formula

a(n) = [x^(n^2)] theta_3(x)^9/(1 - x), where theta_3() is the Jacobi theta function. - Ilya Gutkovskiy, Apr 14 2018