E.g.f.: Product_{i>=1, j>=1} 1 / (1 - x^(i*j) / (i*j)!).

A341505

E.g.f.: Product_{i>=1, j>=1} 1 / (1 - x^(i*j) / (i*j)!).

Terms

    a(0) =1a(1) =1a(2) =4a(3) =14a(4) =77a(5) =427a(6) =3076a(7) =23088a(8) =205316a(9) =1936275a(10) =20611750a(11) =233576818a(12) =2909340750a(13) =38527889389a(14) =551372037898

External references