a(n) has two outer digits 9 and n inner digits 7.

A108904

a(n) has two outer digits 9 and n inner digits 7.

Terms

    a(0) =99a(1) =979a(2) =9779a(3) =97779a(4) =977779a(5) =9777779a(6) =97777779a(7) =977777779a(8) =9777777779a(9) =97777777779a(10) =977777777779

External references