A119131 Numbers k such that the k-th triangular number contains only digits {1,4,9}.

1, 13, 313, 538, 13741, 43386, 48886, 991886, 141415133, 2880781113, 4721227413, 19567549258, 538423521386, 137473211871979931561

Offset

1,2

Links

Table of n, a(n) for n=1..14.

G. Resta, Tridigital Triangular Numbers

Crossrefs

Cf. A000217, A119130. See A119034 for a table of cross-references.

Sequence in context: A142425 A234236 A183522 * A217674 A360324 A241022

Adjacent sequences: A119128 A119129 A119130 * A119132 A119133 A119134

Keyword

nonn,base,more

Author

Giovanni Resta, May 10 2006

Extensions

a(14) from Max Alekseyev, Aug 15 2013

Status

approved