a(n) = (3^(n+2) + 4^(2*n+1))/13.
A386397
a(n) = (3^(n+2) + 4^(2*n+1))/13.
Terms
- a(0) =1a(1) =7a(2) =85a(3) =1279a(4) =20221a(5) =322807a(6) =5162725a(7) =82597039a(8) =1321532941a(9) =21144468007a(10) =338311310965
External references
- oeis: A386397
A386397
a(n) = (3^(n+2) + 4^(2*n+1))/13.