Rectangular array of coefficients in successive iterations of x*exp(x), as read by antidiagonals.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =1a(7) =3a(8) =6a(9) =1a(10) =1a(11) =4a(12) =15a(13) =23a(14) =1a(15) =1a(16) =5a(17) =28a(18) =102a(19) =104a(20) =1a(21) =1a(22) =6a(23) =45a(24) =274a(25) =861a(26) =537a(27) =1a(28) =1a(29) =7