A031467 n-th number k which in base 4 has 2 fewer 0's than 3's.

15, 31, 47, 55, 59, 61, 62, 95, 111, 119, 123, 125, 126, 159, 175, 183, 187, 189, 190, 207, 215, 219, 221, 222, 231, 235, 237, 238, 243, 245, 246, 249, 250, 252, 319, 351, 367, 375, 379, 381, 382, 415, 431, 439, 443, 445, 446