G.f.: Sum_{n>=0} (4*n+3)^n * x^n / (1 + (4*n+3)*x)^n.
A221161
G.f.: Sum_{n>=0} (4*n+3)^n * x^n / (1 + (4*n+3)*x)^n.
Terms
- a(0) =1a(1) =7a(2) =72a(3) =1056a(4) =19968a(5) =460800a(6) =12533760a(7) =392232960a(8) =13872660480a(9) =546979184640
External references
- oeis: A221161