a(n) = 5^(n*(n-1)/2) + 5^(n*(n+1)/2) for n > 0, with a(0) = 1.

A337971

a(n) = 5^(n*(n-1)/2) + 5^(n*(n+1)/2) for n > 0, with a(0) = 1.

Terms

    a(0) =1a(1) =6a(2) =130a(3) =15750a(4) =9781250a(5) =30527343750

External references