a(n) = 6*(10^(2*n+1)-1)/9 - 4*10^n.

A332162

a(n) = 6*(10^(2*n+1)-1)/9 - 4*10^n.

Terms

    a(0) =2a(1) =626a(2) =66266a(3) =6662666a(4) =666626666a(5) =66666266666

External references