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 A116350 #7 Jul 17 2021 01:45:06 %S A116350 33,64,45211541,54788456,78317868,72388446037855609175404258, %T A116350 73247326752475247326752673,75267524732673267524732473, %U A116350 76126405447292905676080888,42053270820132695893502981749304 %N A116350 Numbers k such that k*(k+4) gives the concatenation of two numbers m and m+9. %e A116350 78317868 * 78317872 = 61336887//61336896, where // denotes concatenation. %Y A116350 Cf. A116187, A116337, A116349, A116351. %K A116350 nonn,base %O A116350 1,1 %A A116350 _Giovanni Resta_, Feb 06 2006