A119223 Numbers k such that the k-th triangular number contains only digits {5,6,9}.

3, 10, 11, 34, 36, 105, 109, 114, 3363, 13834, 438109, 1383471, 3622034, 10954411, 11537388, 33336636, 105517363, 141114114, 3333366765, 3333333366663363, 333645229535671903

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base
• more

Links

• Giovanni Resta, Tridigital Triangular Numbers.

Crossrefs

Cf. A000217, A119222. See A119034 for a table of cross-references.

Extensions

a(21) from Tyler Busby, Mar 31 2023