A054227 Number of positive integers <= 2^n of form x^2 + 13 y^2.

1, 1, 2, 2, 6, 10, 19, 32, 58, 105, 194, 364, 682, 1295, 2467, 4723, 9059, 17448, 33706, 65256, 126643, 246179, 479336, 934603, 1824646, 3566467, 6978040, 13666391, 26788334, 52551600, 103168475, 202676349, 398411711, 783639902, 1542192977