A119104 - OEIS

A119104

Numbers k such that the k-th triangular number contains only digits {1,2,6}.

%I #8 Jul 13 2021 01:24:42

%S 1,3,6,11,36,66,111,651,666,1563,1588,5766,6651,6666,15563,15888,

%T 36366,65766,66651,66666,205748,363666,576406,657666,666651,666666,

%U 6657666,6666651,6666666,18014806,36394123,66576666,66666651,66666666

%N Numbers k such that the k-th triangular number contains only digits {1,2,6}.

%H G. Resta, <a href="http://www.numbersaplenty.com/tr/tr126.html">Tridigital Triangular Numbers</a>

%Y Cf. A000217, A119103. See A119034 for a table of cross-references.

%K nonn,base

%O 1,2

%A _Giovanni Resta_, May 10 2006