G.f.: A(x,y) = Sum_{n>=0} x^n * Product_{k=1..n} (k + x*y) / (1 + k*x*y), as a triangle read by rows.

A231171

G.f.: A(x,y) = Sum_{n>=0} x^n * Product_{k=1..n} (k + x*y) / (1 + k*x*y), as a triangle read by rows.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =-3a(5) =24a(6) =-25a(7) =6a(8) =120a(9) =-190a(10) =90a(11) =-12a(12) =720a(13) =-1526a(14) =1095a(15) =-300a(16) =24a(17) =5040a(18) =-13356a(19) =12915a(20) =-5490a(21) =960a(22) =-48a(23) =40320a(24) =-128052a(25) =156100a(26) =-90930a(27) =25500a(28) =-3000a(29) =96

External references