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).
0, 1, 3, 12, 44, 165, 615, 2296, 8568, 31977, 119339, 445380, 1662180, 6203341
1 seqfan posts
Thu Nov 19 17:19:12 CET 2009 [seqfan] detective work related to Creighton Dement's "Floretions"