A119211 - OEIS

%I #7 Jul 13 2021 21:30:28

%S 3,11,36,976,1236,3048,964131,36536961224668,123828734689848,

%T 299247973315331

%N Numbers k such that the k-th triangular number contains only digits {4,6,7}.

%C Next term exceeds 1.4*10^16.

%H G. Resta, <a href="http://www.numbersaplenty.com/tr/tr467.html">Tridigital Triangular Numbers</a>

%Y Cf. A000217, A119210. See A119034 for a table of cross-references.

%K nonn,base,more

%O 1,1

%A _Giovanni Resta_, May 10 2006