A119225 Numbers k such that the k-th triangular number contains only digits {5,7,8}.

10, 12, 107, 125, 132, 389, 1332, 3892, 10572, 10749, 13250, 13332, 105714, 133332, 1255050, 1333332, 4208987, 13333332, 107497707, 133333332, 1054396107, 1333333332, 10843226972, 13333333332, 133333333332

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base

Links

• G. Resta, Tridigital Triangular Numbers

Crossrefs

Cf. A000217, A119224. See A119034 for a table of cross-references.