A168496 The positions of non-single or nonisolated numbers in A001477.
1, 2, 4, 6, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 32, 33, 34, 35, 36, 37, 39, 40, 41, 42, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 69, 70, 71, 72, 74, 75, 76, 77, 78, 79, 81, 82, 83, 85, 86, 87
Offset: 1
Formula
a(n) = 1+A167707(n).
Extensions
Formula corrected by R. J. Mathar, Jun 04 2010