a(n) is the concatenation of the phi(n) numbers between 1 and n that are relatively prime to n.

A061097

a(n) is the concatenation of the phi(n) numbers between 1 and n that are relatively prime to n.

Terms

    a(0) =1a(1) =1a(2) =12a(3) =13a(4) =1234a(5) =15a(6) =123456a(7) =1357a(8) =124578a(9) =1379a(10) =12345678910a(11) =15711a(13) =13591113a(14) =12478111314a(15) =13579111315a(17) =157111317

External references