A sum over partitions (q=10), see first comment.

A221579

A sum over partitions (q=10), see first comment.

Terms

    a(0) =1a(1) =9a(2) =99a(3) =990a(4) =9990a(5) =99891a(6) =999900a(7) =9998901a(8) =99998910a(9) =999989010a(10) =9999989010a(11) =99999889110a(12) =999999890109

External references