a(0) = 0; a(n) = 4^(n-1) + (1/n) * Sum_{k=1..n-1} binomial(n,k)^2 * 4^(k-1) * (n-k) * a(n-k).
A333983
a(0) = 0; a(n) = 4^(n-1) + (1/n) * Sum_{k=1..n-1} binomial(n,k)^2 * 4^(k-1) * (n-k) * a(n-k).
Terms
- a(0) =0a(1) =1a(2) =6a(3) =64a(4) =1328a(5) =46336a(6) =2423040a(7) =177379840a(8) =17314109440
External references
- oeis: A333983