A119172 Triangular numbers composed of digits {2,6,7}.

6, 66, 276, 666, 7626, 6666726, 77666666626, 2662627722726, 2777672627676766, 77772662277672726, 6622726277766676626, 672667762262676277666726

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base
• more

Comments

a(13) > 10^40. - Tyler Busby, Mar 29 2023

Links

• Giovanni Resta, Tridigital Triangular Numbers.

Crossrefs

Cf. A000217, A058462, A119173. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119173(n)). - Tyler Busby, Mar 29 2023