a(n) = n minus (number of 1's in binary expansion of n). Also highest power of 2 dividing n!.
0, 0, 1, 1, 3, 3, 4, 4, 7, 7, 8, 8, 10, 10, 11, 11, 15, 15, 16, 16, 18, 18, 19, 19, 22, 22, 23
1 seqfan posts
Tue Jun 15 03:40:11 CEST 2010 [seqfan] Re: Concerns about some recent comments by Jaroslav Krizek