Triangle read by rows. A generalization of unsigned Lah numbers, called L[4,1].

Terms

a(0) =1a(1) =2a(2) =1a(3) =12a(4) =12a(5) =1a(6) =120a(7) =180a(8) =30a(9) =1a(10) =1680a(11) =3360a(12) =840a(13) =56a(14) =1a(15) =30240a(16) =75600a(17) =25200a(18) =2520a(19) =90a(20) =1a(21) =665280a(22) =1995840a(23) =831600a(24) =110880a(25) =5940a(26) =132a(27) =1a(28) =17297280a(29) =60540480