Number of sets of lists (sequences) of n labeled elements with k=3 elements per list.

Terms

a(0) =1a(1) =0a(2) =0a(3) =6a(4) =0a(5) =0a(6) =360a(7) =0a(8) =0a(9) =60480a(10) =0a(11) =0a(12) =19958400a(13) =0a(14) =0a(15) =10897286400a(16) =0a(17) =0a(19) =0a(20) =0a(22) =0a(23) =0a(25) =0a(26) =0a(28) =0a(29) =0