A119051 Triangular numbers composed of digits {0,2,5}.

55, 5050, 25200, 255255, 500500, 50005000, 525220255, 2250500505, 5000050000, 22052205055, 500000500000, 520022025225, 2205022050055, 2225205025200, 5220005220550, 50000005000000, 220500220500055, 550250022200005, 2552552000225055, 5000000050000000

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base

Links

• Giovanni Resta, Tridigital Triangular Numbers.

Crossrefs

Cf. A000217, A058426, A119052. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119052(n)). - Tyler Busby, Mar 31 2023

Extensions

a(19)-a(20) from Tyler Busby, Mar 22 2023