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

1,2

Links

Table of n, a(n) for n=1..23.

Giovanni Resta, Tridigital Triangular Numbers

Formula

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

Mathematica

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

Crossrefs

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

Sequence in context: A230827 A372070 A111484 * A105157 A166386 A280881

Adjacent sequences: A119038 A119039 A119040 * A119042 A119043 A119044

Keyword

nonn,base

Author

Giovanni Resta, May 10 2006

Extensions

a(23) from Tyler Busby, Mar 27 2023

Status

approved