A053955 -id:A053955 - cp's OEIS frontend

A119208 Triangular numbers composed of digits {4,5,9}.

45, 55, 595, 5995, 49455, 55945, 594595, 5559445, 555594445, 9955945495, 55555944445, 95444955595, 5555559444445, 9545454599955, 499594959455595, 549999555454495, 555555594444445, 55555555944444445, 5555555559444444445, 5999995494459499455

Offset: 1

Giovanni Resta, May 10 2006

Giovanni Resta, Tridigital Triangular Numbers.

Cf. A000217, A053955, A119209. See A119033 for a table of cross-references.

Select[Flatten[Table[FromDigits/@Tuples[{4,5,9},n],{n,17}]],OddQ[ Sqrt[ 8#+1]]&] (* The program will take a long time to run. *) (* Harvey P. Dale, May 23 2021 *)

a(n) = A000217(A119209(n)). - Tyler Busby, Mar 25 2023

a(19)-a(20) from Tyler Busby, Mar 25 2023

A053954 Numbers k such that k^2 contains only digits {4,5,9}.

Original entry on oeis.org

2, 3, 7, 212, 2357, 23357, 244038, 678196107, 745281554823038, 703957001491895099962643

Offset: 1

Patrick De Geest, Mar 15 2000

P. De Geest, Squares containing at most three distinct digits, Index entries for related sequences
H. Mishima Squares consisted of 3 different digits [From _Max Alekseyev_, May 18 2009]

Cf. A053955.

Two more terms from Mishima's webpage added by Max Alekseyev, May 18 2009

cp's OEIS Frontend

A119208 Triangular numbers composed of digits {4,5,9}.

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