A119124 - OEIS

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A119124

Numbers k such that the k-th triangular number contains only digits {1,4,5}.

2

1, 5, 9, 10, 101, 298, 301, 1761, 10113, 10114, 15133, 91010, 297134, 3329010, 10406301, 15133698, 30180826, 47989885, 101434130, 301468258, 942805541, 9544151561, 16977369885, 95335633898, 53952648026842114, 101444705287713701, 10144467866887001141, 1014311732698133730065561

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OFFSET

1,2

COMMENTS

a(25) exceeds 1.4*10^16.

LINKS

Table of n, a(n) for n=1..28.

Giovanni Resta, Tridigital Triangular Numbers

CROSSREFS

Cf. A000217, A119123. See A119034 for a table of cross-references.

Sequence in context: A227853 A275240 A175437 * A326769 A331005 A131634

Adjacent sequences: A119121 A119122 A119123 * A119125 A119126 A119127

KEYWORD

nonn,base

AUTHOR

Giovanni Resta, May 10 2006

EXTENSIONS

a(25)-a(28) from Bert Dobbelaere, Mar 15 2026

STATUS

approved