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 A116140 #6 Jul 20 2021 23:44:31 %S A116140 5,7403,8885,12563,41675,54239,2353623,2650793,7717533,527390351115, %T A116140 567933643889,627121279653,671264212463,1335723019653517755, %U A116140 2049430589972661489,2995303155542192885,4026214090447622723 %N A116140 Numbers k such that k concatenated with k-3 gives the product of two numbers which differ by 9. %e A116140 7717533//7717530 = 8784945 * 8784954, where // denotes concatenation. %Y A116140 Cf. A116133, A116139, A116147, A116271. %K A116140 nonn,base %O A116140 1,1 %A A116140 _Giovanni Resta_, Feb 06 2006