a(n) = Sum_{k=0..n} 6^k*N(n,k), with a(0)=1, where N(n,k) = C(n,k) * C(n,k+1)/n are the Narayana numbers (A001263).
A078018
a(n) = Sum_{k=0..n} 6^k*N(n,k), with a(0)=1, where N(n,k) = C(n,k) * C(n,k+1)/n are the Narayana numbers (A001263).
Terms
- a(0) =1a(1) =1a(2) =7a(3) =55a(4) =469a(5) =4237a(6) =39907a(7) =387739a(8) =3858505a(9) =39130777a(10) =402972031a(11) =4202705311a(12) =44299426717a(13) =471189693925
External references
- oeis: A078018