Derived from secondary diagonal of table A124550; a(n) = A124550(n+1,n)/(n+1).

A124559

Derived from secondary diagonal of table A124550; a(n) = A124550(n+1,n)/(n+1).

Terms

    a(0) =1a(1) =1a(2) =5a(3) =51a(4) =869a(5) =22202a(6) =803053a(7) =39901447a(8) =2677520438a(9) =239963727089

External references