A054171 Number of positive integers <= 2^n of form 4 x^2 + 7 y^2.

0, 0, 1, 2, 4, 7, 12, 23, 41, 77, 142, 270, 504, 958, 1834, 3505, 6752, 13016, 25170, 48775, 94718, 184210, 358805, 699919, 1366853, 2672452, 5230345, 10245791, 20088113, 39415538, 77394348, 152067981, 298975703, 588143637, 1157617442

Offset

0,4

Links

Table of n, a(n) for n=0..34.

Index entries for sequences related to populations of quadratic forms

Crossrefs

Cf. A020683.

Sequence in context: A099604 A026790 A054165 * A018080 A226160 A018181

Adjacent sequences: A054168 A054169 A054170 * A054172 A054173 A054174

Keyword

nonn

Author

David W. Wilson

Status

approved