G.f.: A(x) = exp( Sum_{n>=1} A000172(n)*x^n/n ) where Franel number A000172(n) = Sum_{k=0..n} C(n,k)^3.
A166990
G.f.: A(x) = exp( Sum_{n>=1} A000172(n)*x^n/n ) where Franel number A000172(n) = Sum_{k=0..n} C(n,k)^3.
Terms
- a(0) =1a(1) =2a(2) =7a(3) =30a(4) =147a(5) =786a(6) =4472a(7) =26644a(8) =164477a(9) =1044258a(10) =6782484a(11) =44887236a(12) =301782361a(13) =2056250570a(14) =14172792355a(15) =98667874038a(16) =692948001906
External references
- oeis: A166990