A055413 Number of points in Z^7 of norm <= n.

1, 15, 953, 12435, 88273, 394691, 1405325, 4031123, 10248133, 23120727, 48218513, 93417543, 172039681, 299505299, 503363697, 813950491, 1279144845, 1950568311, 2912136485, 4244109647, 6080556217, 8545686087, 11835454865

Offset: 0

Author

David W. Wilson

Keywords

• nonn

Links

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

Crossrefs

Column k=7 of A302997.

Formula

a(n) = [x^(n^2)] theta_3(x)^7/(1 - x), where theta_3() is the Jacobi theta function. - Ilya Gutkovskiy, Apr 14 2018