A155905 Numbers n such that it is possible to append a single digit to the end of 2^n to make it prime.

0, 1, 2, 3, 4, 6, 7, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 24, 25, 27, 30, 31, 33, 36, 38, 42, 43, 46, 49, 50, 51, 54, 55, 57, 58, 60, 64, 65, 73, 74, 84, 93, 106, 108, 123, 126, 129, 139, 150, 162, 183, 187, 196, 198, 220, 271, 273, 279, 301, 312, 379, 392