a(1) = 1; a(n) = Sum (n+k)!a(k)/(2k)!, k = 1..n-1.
1, 3, 27, 339, 5553, 112761, 2736099, 77252175, 2488315257, 90053238033
1 seqfan posts
Sun Mar 15 02:46:16 CET 2009 [seqfan] A069693 .. A069700 (triangular numbers of the form abb...bc) are fini and full