Triangle of Lah numbers.

Terms

a(0) =-1a(1) =2a(2) =1a(3) =-6a(4) =-6a(5) =-1a(6) =24a(7) =36a(8) =12a(9) =1a(10) =-120a(11) =-240a(12) =-120a(13) =-20a(14) =-1a(15) =720a(16) =1800a(17) =1200a(18) =300a(19) =30a(20) =1a(21) =-5040a(22) =-15120a(23) =-12600a(24) =-4200a(25) =-630a(26) =-42a(27) =-1a(28) =40320a(29) =141120