a(n) = 5a(n-1) - 5a(n-2) + a(n-3) + 2*(-1)^(n+1), alternatively a(n) = 3a(n-1) + 3a(n-2) - a(n-3).
1, 5, 18, 68, 253, 945, 3526, 13160, 49113, 183293, 684058, 2552940, 9527701
1 seqfan posts
Thu Nov 19 17:19:12 CET 2009 [seqfan] detective work related to Creighton Dement's "Floretions"