a(n) is the concatenation of n 1's, 0, n 1's and 0.

A173521

a(n) is the concatenation of n 1's, 0, n 1's and 0.

Terms

    a(0) =0a(1) =1010a(2) =110110a(3) =11101110a(4) =1111011110a(5) =111110111110

External references