A119227 Numbers k such that the k-th triangular number contains only digits {5,7,9}.

10, 34, 109, 3944509, 4421714, 10730871349, 12472189525, 3893060383753634

Offset

1,1

Comments

Next term exceeds 1.4*10^16.

Links

Table of n, a(n) for n=1..8.

G. Resta, Tridigital Triangular Numbers

Crossrefs

Cf. A000217, A119226. See A119034 for a table of cross-references.

Sequence in context: A020877 A119171 A119229 * A218631 A166066 A232583

Adjacent sequences: A119224 A119225 A119226 * A119228 A119229 A119230

Keyword

nonn,base,more

Author

Giovanni Resta, May 10 2006

Status

approved