A018858 3^a(n) is smallest power of 3 beginning with n.

0, 3, 1, 14, 10, 8, 6, 4, 2, 21, 19, 17, 38, 15, 13, 34, 11, 32, 9, 30, 7, 28, 49, 5, 26, 47, 3, 24, 45, 66, 22, 43, 108, 20, 85, 41, 106, 18, 83, 39, 104, 60, 16, 81, 37, 102, 14, 123, 79, 35, 100, 56, 12, 77, 33, 142, 98, 54, 10, 75, 31, 140, 96, 52, 8, 117, 73, 29, 138, 94, 50, 6