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A218402 Numbers n such that the n-th triangular number contains only digits {0,7,9}. 2
44, 426096444, 12641976109035254775 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

No other terms below 1.4*10^20.

LINKS

Table of n, a(n) for n=1..3.

G. Resta, Tridigital Triangular Numbers

CROSSREFS

Cf. A000217, A218401. See A119034 for a table of cross-references.

Sequence in context: A001782 A172910 A119058 * A131994 A037940 A037218

Adjacent sequences:  A218399 A218400 A218401 * A218403 A218404 A218405

KEYWORD

base,nonn,more,hard,bref

AUTHOR

Max Alekseyev, Oct 28 2012

STATUS

approved

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Last modified June 12 10:58 EDT 2021. Contains 344947 sequences. (Running on oeis4.)