a(n) = 7^n*(n+1)*(81*n^4+684*n^3+1401*n^2+434*n+40)/40.
A361608
a(n) = 7^n*(n+1)*(81*n^4+684*n^3+1401*n^2+434*n+40)/40.
Terms
- a(0) =1a(1) =924a(2) =48804a(3) =1337014a(4) =26622288a(5) =437049228a(6) =6295986235a(7) =82489361052
External references
- oeis: A361608