Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,2,2.

A037551

Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 1,2,2.

Terms

    a(0) =1a(1) =12a(2) =122a(3) =1221a(4) =12212a(5) =122122a(6) =1221221a(7) =12212212a(8) =122122122a(9) =1221221221a(10) =12212212212a(11) =122122122122

External references