A054193 Number of positive integers <= 2^n of form 9 x^2 + 9 y^2.

0, 0, 0, 0, 1, 2, 4, 8, 14, 26, 48, 87, 162, 303, 569, 1076, 2044, 3903, 7485, 14401, 27778, 53724, 104135, 202242, 393450, 766556, 1495546, 2921307, 5712535, 11181823, 21907443, 42957050, 84296463, 165535959, 325281762, 639576071