For n>=1, a(n) = n + 2 + Sum_{i=1..n-1} a(i)*a(n-i).

A173998

For n>=1, a(n) = n + 2 + Sum_{i=1..n-1} a(i)*a(n-i).

Terms

    a(0) =3a(1) =13a(2) =83a(3) =673a(4) =6203a(5) =61613a(6) =642683a(7) =6940673a(8) =76930803a(9) =870136013a(10) =10002590883a(11) =116521027873

External references