A226505 Irregular triangle read by rows: T(n,k) = number of set partitions of [1..n] with intertwining weight k.
1, 1, 2, 5, 14, 1, 42, 9, 1, 132, 55, 14, 2, 429, 286, 120, 35, 6, 1, 1430, 1365, 819, 364, 119, 35, 7, 1, 4862, 6188, 4900, 2940, 1394, 586, 203, 59, 13, 2, 16796, 27132, 26928, 20400, 12576, 6846, 3246, 1358, 493, 153, 38, 8, 1
Offset: 0
Examples
Triangle begins: 1 1 2 5 14 1 42 9 1 132 55 14 2 429 286 120 35 6 1 1430 1365 819 364 119 35 7 1 4862 6188 4900 2940 1394 586 203 59 13 2 16796 27132 26928 20400 12576 6846 3246 1358 493 153 38 8 1 ...
Links
- B. Chern, P. Diaconis, D. M. Kane, and R. C. Rhoades, Closed expressions for averages of set partition statistics, arXiv:1304.4309 [math.CO], 2013.