a(n+2) = 81*a(n+1) - a(n), a(1)=0, a(2)=9.

A154026

a(n+2) = 81*a(n+1) - a(n), a(1)=0, a(2)=9.

Terms

    a(0) =0a(1) =9a(2) =729a(3) =59040a(4) =4781511a(5) =387243351a(6) =31361929920

External references