Coefficients of expansion polynomial:p(x,t)=Exp[ -t^2* x](1 - t)^(-x)/x.

Terms

a(0) =1a(1) =-1a(2) =1a(3) =2a(4) =-3a(5) =1a(6) =6a(7) =11a(8) =-6a(9) =1a(10) =24a(11) =10a(12) =35a(13) =-10a(14) =1a(15) =120a(16) =94a(17) =-45a(18) =85a(19) =-15a(20) =1a(21) =720a(22) =756a(23) =364a(24) =-315a(25) =175a(26) =-21a(27) =1a(28) =5040a(29) =6348