G.f.: x^3/(1-2*x+x^3-x^4). Recurrence: a(n) = 2*a(n-1)-a(n-3)+a(n-4).
1, 2, 4, 7, 13, 24, 45, 84, 157, 293, 547, 1021, 1906, 3558, 6642, 12399, 23146
2 seqfan posts
Thu Sep 16 19:44:47 CEST 2010 [seqfan] Initial Substrings of n-bit Binary Numbers Not Divisible by k