Base-3 representation of a(n) is the concatenation of the base-3 representations of 1, 2, ..., n, n-1, ..., 1.

A260853

Base-3 representation of a(n) is the concatenation of the base-3 representations of 1, 2, ..., n, n-1, ..., 1.

Terms

    a(0) =0a(1) =1a(2) =16a(3) =439a(4) =35350a(5) =2864599a(6) =232046890a(7) =18795930559

External references