A119166 Triangular numbers composed of digits {2,5,7}.

55, 2775, 255255, 577275, 572755525755, 2577527227575, 727275225222727525, 2257227755272522252275, 52722757572552577725225, 272527775757277272275522727772752527575

Offset

1,1

Comments

a(11) > 10^40. - Tyler Busby, Mar 28 2023

Links

Table of n, a(n) for n=1..10.

Giovanni Resta, Tridigital Triangular Numbers.

Formula

a(n) = A000217(A119167(n)). - Tyler Busby, Mar 28 2023

Crossrefs

Cf. A000217, A030485, A119167. See A119033 for a table of cross-references.

Sequence in context: A212788 A131557 A231853 * A027548 A231640 A076657

Adjacent sequences: A119163 A119164 A119165 * A119167 A119168 A119169

Keyword

nonn,base,more

Author

Giovanni Resta, May 10 2006

Extensions

a(10) from Tyler Busby, Mar 28 2023

Status

approved