A119041 Triangular numbers composed of digits {0,1,6}.

1, 6, 10, 66, 666, 10011, 16110, 66066, 600060, 6601161, 10006101, 11066160, 660061611, 1001661661, 1061660160, 1100016060, 1660061010, 1001000010660, 1066006600011, 10010000160006, 106001000601616, 60660116660011611, 1660616006066010601060060

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base

Links

• Giovanni Resta, Tridigital Triangular Numbers

Crossrefs

Cf. A000217, A058418, A119042. See A119033 for a table of cross-references.

Programs

Mathematica

Rest[Select[FromDigits/@Tuples[{0,1,6},17],OddQ[Sqrt[8#+1]]&]] (* Harvey P. Dale, Jan 14 2017 *)

Formula

a(n) = A000217(A119042(n)). - Tyler Busby, Mar 27 2023

Extensions

a(23) from Tyler Busby, Mar 27 2023