a(n) is least number > 0 such that the concatenation of a(1) ... a(n) is 13-gonal: (11n^2 - 9n)/2.

A264842

a(n) is least number > 0 such that the concatenation of a(1) ... a(n) is 13-gonal: (11n^2 - 9n)/2.

Terms

    a(0) =1a(1) =3a(2) =36a(3) =54765a(4) =123152388

External references