a(n) = 4^(n*(n-1)/2) + 4^(n*(n+1)/2) for n > 0, with a(0) = 1.

A337951

a(n) = 4^(n*(n-1)/2) + 4^(n*(n+1)/2) for n > 0, with a(0) = 1.

Terms

    a(0) =1a(1) =5a(2) =68a(3) =4160a(4) =1052672a(5) =1074790400

External references