G.f.: exp( Sum_{n>=1} (x^n/n) / [Sum_{k=0..n} C(n,k)^2*(-x)^k] ).
A199164
G.f.: exp( Sum_{n>=1} (x^n/n) / [Sum_{k=0..n} C(n,k)^2*(-x)^k] ).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =5a(4) =17a(5) =77a(6) =448a(7) =3274a(8) =29326a(9) =313768a(10) =3929226a(11) =56701093a(12) =930803798a(13) =17196523994a(14) =354410799300
External references
- oeis: A199164