a(n) = 10*a(n-1) + 10*a(n-2), with a(0)=1, a(1)=9, a(2)=99.

A155157

a(n) = 10*a(n-1) + 10*a(n-2), with a(0)=1, a(1)=9, a(2)=99.

Terms

    a(0) =1a(1) =9a(2) =99a(3) =1080a(4) =11790a(5) =128700a(6) =1404900a(7) =15336000a(8) =167409000a(9) =1827450000a(10) =19948590000a(11) =217760400000

External references