Expansion of e.g.f. (1 + y)^(1 + x).

Terms

a(0) =1a(1) =1a(2) =1a(3) =0a(4) =1a(5) =1a(6) =0a(7) =-1a(8) =0a(9) =1a(10) =0a(11) =2a(12) =-1a(13) =-2a(14) =1a(15) =0a(16) =-6a(17) =5a(18) =5a(19) =-5a(20) =1a(21) =0a(22) =24a(23) =-26a(24) =-15a(25) =25a(26) =-9a(27) =1a(28) =0a(29) =-120