A119118 Numbers k such that the k-th triangular number contains only digits {1,3,7}.

1, 2, 18, 58, 1853, 5853, 1620578, 485216058, 1243473981, 2747265466, 595277030253, 789599540493, 2573455929746, 48450258487106

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base
• more

Comments

Next term is greater than 4.4*10^18. - Max Alekseyev, Oct 15 2012

Links

• G. Resta, Tridigital Triangular Numbers

Crossrefs

Cf. A000217, A119117. See A119034 for a table of cross-references.