A327003 Irregular triangle read by rows in which the n-th row lists multinomials for partitions of 3n which have only parts which are multiples of 3, in Hindenburg order.
1, 1, 1, 10, 1, 84, 280, 1, 220, 462, 9240, 15400, 1, 455, 5005, 50050, 210210, 1401400, 1401400, 1, 816, 18564, 185640, 24310, 4084080, 13613600, 2858856, 85765680, 285885600, 190590400, 1, 1330, 54264, 542640, 293930, 24690120, 82300400, 32332300, 135795660, 2715913200, 4526522000, 3802278480, 38022784800, 76045569600, 36212176000
Offset: 0
Examples
The irregular triangle starts: [0] [1] [1] [1] [2] [1, 10] [3] [1, 84, 280] [4] [1, 220, 462, 9240, 15400] [5] [1, 455, 5005, 50050, 210210, 1401400, 1401400] [6] [1, 816, 18564, 185640, 24310, 4084080, 13613600, 2858856, 85765680, 285885600, 190590400]
Crossrefs
Programs
Formula
Row of lengths are in A000041.
Comments