Numbers k such that the k-th triangular number contains only digits {1,3,9}.

A119122

Numbers k such that the k-th triangular number contains only digits {1,3,9}.

Terms

    a(0) =1a(1) =2a(2) =13a(3) =621a(4) =4458a(5) =489884458a(6) =632318261a(7) =893464178a(8) =16684802253

External references