A054161 Number of positive integers <= 2^n of form 3 x^2 + 3 y^2.

0, 0, 1, 2, 4, 7, 12, 21, 38, 69, 126, 234, 437, 825, 1565, 2982, 5710, 10967, 21138, 40842, 79099, 153510, 298435, 581095, 1133110, 2212231, 4324045, 8460649, 16570079, 32480219, 63717408, 125088092, 245735287, 483050536, 950104880