A050128 a(n)=[ a(n-1)/2 ] if this is not among 0,a(1),...,a(n-1), else a(n)=2*n.

1, 4, 2, 8, 10, 5, 14, 7, 3, 20, 22, 11, 26, 13, 6, 32, 16, 36, 18, 9, 42, 21, 46, 23, 50, 25, 12, 56, 28, 60, 30, 15, 66, 33, 70, 35, 17, 76, 38, 19, 82, 41, 86, 43, 90, 45, 94, 47, 98, 49, 24, 104, 52, 108, 54, 27, 114, 57, 118, 59, 29, 124