A054150 Number of positive integers <= 2^n of the form x^2 + 5*y^2.

1, 1, 2, 4, 7, 13, 22, 40, 73, 132, 245, 458, 864, 1638, 3123, 5979, 11484, 22140, 42773, 82865, 160809, 312659, 608857, 1187323, 2318344, 4531879, 8867913, 17369053, 34048772, 66799240, 131146379, 257651913, 506503984, 996288321

Offset

0,3

Links

Table of n, a(n) for n=0..33.

Index entries for sequences related to populations of quadratic forms

Crossrefs

Cf. A020669.

Sequence in context: A254007 A372782 A001036 * A130709 A051013 A128609

Adjacent sequences: A054147 A054148 A054149 * A054151 A054152 A054153

Keyword

nonn

Author

David W. Wilson

Status

approved