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 A116180 #8 Jul 20 2021 23:47:50 %S A116180 7137,7767,47783068991048776635,48797525371338932241, %T A116180 55658688122404752991,56753136503494828605,85555875266989354735, %U A116180 86911515887391841491,95992713077544748491,97428345698747155255 %N A116180 Numbers k such that k concatenated with k+3 gives the product of two numbers which differ by 7. %C A116180 Also numbers k such that k concatenated with k-5 gives the product of two numbers which differ by 9. %C A116180 Also numbers k such that k concatenated with k+9 gives the product of two numbers which differ by 5. %e A116180 7767//7770 = 8810 * 8817, where // denotes concatenation. %e A116180 7767//7762 = 8809 * 8818. %e A116180 7767//7776 = 8811 * 8816. %Y A116180 Cf. A116167, A116179, A116181, A116133, A116311. %Y A116180 Cf. A116114, A116126, A116133, A116258. %Y A116180 Cf. A116207, A116187, A116174, A116351. %K A116180 nonn,base %O A116180 1,1 %A A116180 _Giovanni Resta_, Feb 06 2006 %E A116180 Edited by _N. J. A. Sloane_, Apr 12 2007