a(0) = 1; for n>=1, a(n) = Sum_{k=0..n} 7^k*N(n,k), where N(n,k)=(1/n)*C(n,k)*C(n,k+1) are the Narayana numbers (A001263).
A081178
a(0) = 1; for n>=1, a(n) = Sum_{k=0..n} 7^k*N(n,k), where N(n,k)=(1/n)*C(n,k)*C(n,k+1) are the Narayana numbers (A001263).
Terms
- a(0) =1a(1) =1a(2) =8a(3) =71a(4) =680a(5) =6882a(6) =72528a(7) =788019a(8) =8766248a(9) =99362894a(10) =1143498224a(11) =13326176998a(12) =156950554384
External references
- oeis: A081178