Repunits concatenated with A000422, where A000422 is the concatenation of numbers from n down to 1.

A078568

Repunits concatenated with A000422, where A000422 is the concatenation of numbers from n down to 1.

Terms

    a(0) =11a(1) =1121a(2) =111321a(3) =11114321a(4) =1111154321a(5) =111111654321

External references