a(0) = 1; a(n) = (1/3) * Sum_{k=1..n} binomial(n,k) * (4^k-1) * a(n-k).
A337556
a(0) = 1; a(n) = (1/3) * Sum_{k=1..n} binomial(n,k) * (4^k-1) * a(n-k).
Terms
- a(0) =1a(1) =1a(2) =7a(3) =57a(4) =607a(5) =8121a(6) =130527a(7) =2447257a(8) =52435327a(9) =1263925881a(10) =33851510047a(11) =997303255257
External references
- oeis: A337556