A119045 Triangular numbers composed of digits {0,1,8}.

1, 10, 1081, 8001, 10011, 81810, 108811, 1188111, 8018010, 8801110, 10888111, 80118811, 88000011, 800180010, 881811010, 1088881111, 10808101800, 80001800010, 81108010180, 108888811111, 810008010801, 880818181011, 888000000111, 8000018000010, 10888888111111

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base

Links

• Giovanni Resta, Tridigital Triangular Numbers

Crossrefs

Cf. A000217, A058422, A119046. See A119033 for a table of cross-references.

Programs

Mathematica

Rest[Select[FromDigits/@Tuples[{0,1,8},12],OddQ[Sqrt[8#+1]]&]] (* or *) Select[Accumulate[Range[1328*10^3]],SubsetQ[{0,1,8}, IntegerDigits[ #]]&](* Harvey P. Dale, May 06 2019 *)

Formula

a(n) = A000217(A119046(n)). - Michel Marcus, Mar 11 2023

Extensions

a(23)-a(25) from Tyler Busby, Mar 11 2023