A119069 Triangular numbers composed of digits {0,3,9}.

3, 300, 903, 990, 3003, 33930, 39903, 339900, 930930, 39033030, 990903903, 3909003990, 3993990000, 33003300903, 39999939903, 90993993300, 3390003090090, 99990099000330, 90009933903093903, 399939399933939330, 303300903903330099003, 3309000900300303999300

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base

Links

• Giovanni Resta, Tridigital Triangular Numbers

Crossrefs

Cf. A000217, A058434, A119070. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119070(n)). - Michel Marcus, Mar 22 2023

Extensions

a(21)-a(22) from Tyler Busby, Mar 22 2023