Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 2,1,0.

A037527

Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 2,1,0.

Terms

    a(0) =2a(1) =21a(2) =210a(3) =2102a(4) =21021a(5) =210210a(6) =2102102a(7) =21021021a(8) =210210210a(9) =2102102102a(10) =21021021021a(11) =210210210210

External references