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

1,1

Links

Table of n, a(n) for n=1..20.

Giovanni Resta, Tridigital Triangular Numbers.

Formula

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

Crossrefs

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

Sequence in context: A013537 A056567 A119081 * A119083 A037156 A116110

Adjacent sequences: A119048 A119049 A119050 * A119052 A119053 A119054

Keyword

nonn,base

Author

Giovanni Resta, May 10 2006

Extensions

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

Status

approved