A119093 Triangular numbers composed of digits {0,7,8}.

78, 780, 8778, 887778, 88877778, 870800778, 7007800078, 8008780080, 8888777778, 770800800078, 888887777778, 70870887770880, 88888877777778, 7808778880700878, 8888888777777778, 888888887777777778, 70888000778807080078, 88888888877777777778

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base

Links

• Giovanni Resta, Tridigital Triangular Numbers.

Crossrefs

Cf. A000217, A119094. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119094(n)). - Tyler Busby, Mar 31 2023

Extensions

a(17)-a(18) from Tyler Busby, Mar 23 2023