a(2n) = 2*4^n-1, a(2n+1) = (2^(n+1)+1)^2; interlaces A083420 with A028400.
1, 9, 7, 25, 31, 81, 127, 289, 511, 1089, 2047, 4225, 8191, 16641, 32767, 66049
1 seqfan posts
Thu Nov 19 17:19:12 CET 2009 [seqfan] detective work related to Creighton Dement's "Floretions"