One-half the number of permutations of length n with exactly 2 rising or falling successions.
0, 0, 0, 1, 5, 24, 128, 835, 6423, 56410, 554306, 6016077, 71426225, 920484892
1 seqfan posts
Fri Oct 29 05:35:16 CEST 2010 [seqfan] Implementing first 500 sequences in Java