A119087 Triangular numbers composed of digits {0,6,7}.

6, 66, 666, 6670, 66066, 600060, 67007676, 670677000, 66067760760, 76666077676, 76670776666, 660067006660776, 7600067000007076, 6700677067067607000, 60660060606000770770776700, 776600760606070666600067770, 7766770606766667760666707766

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base

Links

• Giovanni Resta, Tridigital Triangular Numbers.

Crossrefs

Cf. A000217, A058450, A119088. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119088(n)). - Tyler Busby, Mar 31 2023

Extensions

a(16)-a(17) from Tyler Busby, Mar 23 2023