a(n) = Sum_{k=0..n} (-1)^(n-k)*binomial(n,k)*2^(2^k).
A000371
a(n) = Sum_{k=0..n} (-1)^(n-k)*binomial(n,k)*2^(2^k).
Terms
- a(0) =2a(1) =2a(2) =10a(3) =218a(4) =64594a(5) =4294642034
External references
- oeis: A000371
A000371
a(n) = Sum_{k=0..n} (-1)^(n-k)*binomial(n,k)*2^(2^k).