a(n) = (27^n - 3*9^n - 3*12^n)/6 + 6^n.
A342405
a(n) = (27^n - 3*9^n - 3*12^n)/6 + 6^n.
Terms
- a(0) =0a(1) =45a(2) =2268a(3) =76221a(4) =2245320a(5) =62858025a(6) =1723364748a(7) =46836754821
External references
- oeis: A342405
A342405
a(n) = (27^n - 3*9^n - 3*12^n)/6 + 6^n.