A053945 -id:A053945 - cp's OEIS frontend

A119186 Triangular numbers composed of digits {3,5,6}.

3, 6, 36, 55, 66, 666, 3655, 5356, 5565, 6555, 333336, 3635556, 5656566, 35536665, 56365653, 56663335, 63365653, 655636366, 53533355655, 55663663653, 533533653555, 555533363556, 6653355565366, 555665666566566, 35356355566555653, 653366333366663536656

Offset: 1

Giovanni Resta, May 10 2006

Giovanni Resta, Tridigital Triangular Numbers

Cf. A000217, A053945, A119187. See A119033 for a table of cross-references.

Table[Select[FromDigits/@Tuples[{3,5,6},n],OddQ[Sqrt[8#+1]]&],{n,15}]//Flatten (* Harvey P. Dale, Aug 03 2021 *)

a(n) = A000217(A119187(n)). - Tyler Busby, Mar 24 2023

a(25)-a(26) from Tyler Busby, Mar 24 2023

A053944 Numbers k such that k^2 contains only digits {3,5,6}.

Original entry on oeis.org

6, 256, 744, 1834, 18806, 23166, 23566, 256194, 2357194, 2523166, 187979694, 2310098166, 19121548934, 25209786895834, 23527926717739784

Offset: 1

Patrick De Geest, Mar 15 2000

Patrick De Geest, Squares containing at most three distinct digits, Index entries for related sequences.
Hisanori Mishima, Sporadic tridigital solutions.
Author?, Source(txt)

Cf. A053945.

One more term from Ryan H. Richter (bobort(AT)bigfoot.com), Jan 25 2001, who remarks that there are no more terms less than 4000000000
More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 03 2005
One more term from Jon E. Schoenfield, Sep 04 2006
a(15) from Mishima's website added by Elmo R. Oliveira, Jul 17 2025

cp's OEIS Frontend

A119186 Triangular numbers composed of digits {3,5,6}.

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