This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A119084 #8 Jul 13 2021 01:25:36
%S A119084 10,100,1000,10000,100000,1000000,1056485,10000000,40212075,100000000,
%T A119084 1000000000,10000000000,100000000000,100549051600,1000000000000,
%U A119084 10000000000000,100000000000000,421438146839024,1000000000000000
%N A119084 Numbers k such that the k-th triangular number contains only digits {0,5,8}.
%H A119084 G. Resta, <a href="http://www.numbersaplenty.com/tr/tr058.html">Tridigital Triangular Numbers</a>
%Y A119084 Cf. A000217, A119083. See A119034 for a table of cross-references.
%K A119084 nonn,base
%O A119084 1,1
%A A119084 _Giovanni Resta_, May 10 2006