A119145 Numbers k such that the k-th triangular number contains only digits {1,6,9}.

1, 3, 11, 13, 36, 1386, 1411, 1543, 438433, 445241, 5685366, 19849388, 36385963, 154671711, 199808366, 1408518133, 3497461911, 184180138433, 1350308625456, 4892835517288, 11505747426366, 118253893522536, 447137831091711

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base

Links

• G. Resta, Tridigital Triangular Numbers

Crossrefs

Cf. A000217, A119144. See A119034 for a table of cross-references.