%I #8 Jul 13 2021 07:28:36
%S 1,5,10,13,34,101,109,138,1738,10114,19794,1011090,1019010,1054130,
%T 1091010,34406858,178858133,565606858,4289521091010,55841058721258
%N Numbers k such that the kth triangular number contains only digits {1,5,9}.
%C Next term exceeds 1.4*10^16.
%H G. Resta, <a href="http://www.numbersaplenty.com/tr/tr159.html">Tridigital Triangular Numbers</a>
%Y Cf. A000217, A119138. See A119034 for a table of crossreferences.
%K nonn,base,more
%O 1,2
%A _Giovanni Resta_, May 10 2006
