a(n) = (2^(2*n+1) - 1)*(3^(n+1) - 1)/2.
A269255
a(n) = (2^(2*n+1) - 1)*(3^(n+1) - 1)/2.
Terms
- a(0) =1a(1) =28a(2) =403a(3) =5080a(4) =61831a(5) =745108a(6) =8952763a(7) =107475760a(8) =1289869711a(9) =15479049388a(10) =185750955523
External references
- oeis: A269255