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 A116349 #7 Jul 17 2021 01:45:03 %S A116349 32,66,42755,57243,75425,425074,574924,979530,4301395,5698603,7028668, %T A116349 4925000749,5074999249,7748266576,8511881486,8814851186,7059602159674, %U A116349 7106167933830,7439286611623,7485852385779,46791112884927 %N A116349 Numbers k such that k*(k+3) gives the concatenation of two numbers m and m+9. %Y A116349 Cf. A116193, A116336, A116348, A116350. %K A116349 nonn,base %O A116349 1,1 %A A116349 _Giovanni Resta_, Feb 06 2006