a(n) = Sum_{k=0..n-1} {[x^k] A(x)^(n-k)} * {[x^(n-k-1)] A(x)^(k+1)} for n>0, with a(0)=1, where g.f. A(x) = Sum_{n>=0} a(n)*x^n.
A161881
a(n) = Sum_{k=0..n-1} {[x^k] A(x)^(n-k)} * {[x^(n-k-1)] A(x)^(k+1)} for n>0, with a(0)=1, where g.f. A(x) = Sum_{n>=0} a(n)*x^n.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =8a(4) =46a(5) =333a(6) =2822a(7) =26884a(8) =280778a(9) =3162129a(10) =37962174a(11) =481796692a(12) =6424120440a(13) =89561323131
External references
- oeis: A161881