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A218402
Numbers k such that the k-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 3.7*10^28. - Bert Dobbelaere, Mar 15 2026
LINKS
Table of n, a(n) for n=1..3.
Giovanni 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 May 21 18:28 EDT 2026. Contains 395802 sequences.
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