A119233 - OEIS

%I #9 Jul 13 2021 21:31:25

%S 3,11,36,36817576,365512507857054543

%N Numbers k such that the k-th triangular number contains only digits {6,7,9}.

%C Next term exceeds 4.4*10^17.

%H G. Resta, <a href="http://www.numbersaplenty.com/tr/tr679.html">Tridigital Triangular Numbers</a>

%Y Cf. A000217, A119232. See A119034 for a table of cross-references.

%K nonn,base,more

%O 1,1

%A _Giovanni Resta_, May 10 2006

%E 365512507857054543 from _Max Alekseyev_, Mar 10 2009