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 A116311 #7 Jul 17 2021 01:44:16 %S A116311 8445,8810,69125298546226023971,69855225553525294044, %T A116311 74604750601020544519,75334677608319814592,92496418993920707746, %U A116311 93226346001219977819,97975871048715228294,98705798056014498367 %N A116311 Numbers k such that k*(k+7) gives the concatenation of two numbers m and m+3. %e A116311 8810 * 8817 = 7767//7770, where // denotes concatenation. %Y A116311 Cf. A116180, A116298, A116310, A116312, A116319. %K A116311 nonn,base %O A116311 1,1 %A A116311 _Giovanni Resta_, Feb 06 2006