A054153 Number of positive integers <= 2^n of form x^2 + 9 y^2.

1, 1, 2, 2, 6, 8, 18, 30, 57, 103, 194, 360, 682, 1292, 2464, 4721, 9078, 17481, 33808, 65485, 127116, 247179, 481426, 938950, 1833572, 3584679, 7015237, 13741715, 26940645, 52858250, 103785060, 203913141, 400891200, 788601863, 1552114600

Offset

0,3

Links

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

Index entries for sequences related to populations of quadratic forms

Crossrefs

Cf. A020672.

Sequence in context: A365662 A214932 A322132 * A000673 A355640 A370586

Adjacent sequences: A054150 A054151 A054152 * A054154 A054155 A054156

Keyword

nonn

Author

David W. Wilson

Status

approved