a(n) = [x^(n-1)] Product_{k=1..n} (k + x + 2*k*x^2), for n >= 1.

A322893

a(n) = [x^(n-1)] Product_{k=1..n} (k + x + 2*k*x^2), for n >= 1.

Terms

    a(0) =1a(1) =3a(2) =42a(3) =310a(4) =6165a(5) =74991a(6) =1948268a(7) =33402132a(8) =1070751825a(9) =23818189395a(10) =907365113622

External references