a(0) = 1; a(n) = (1/2) * Sum_{k=1..n} binomial(n,k) * (3^k-1) * a(n-k).
A337555
a(0) = 1; a(n) = (1/2) * Sum_{k=1..n} binomial(n,k) * (3^k-1) * a(n-k).
Terms
- a(0) =1a(1) =1a(2) =6a(3) =43a(4) =408a(5) =4861a(6) =69516a(7) =1159663a(8) =22108848a(9) =474192601a(10) =11300589876a(11) =296237533483
External references
- oeis: A337555