Numbers k such that the k-th triangular number contains only digits {1,7,9}.

A119149

Numbers k such that the k-th triangular number contains only digits {1,7,9}.

Terms

    a(0) =1a(1) =13a(2) =18a(3) =58a(4) =586a(5) =1258a(6) =58613a(7) =1350538a(8) =1414213a(9) =59517693a(10) =1398413386a(11) =5996665693

External references