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 A116175 #6 Jul 20 2021 23:47:32 %S A116175 1122070,1538990,3692998,4422608,1661985831086046580, %T A116175 3508493742205242178,5949206094811297768,11324756194731856386028, %U A116175 44020205992737767475178,55147546334394567747178 %N A116175 Numbers k such that k concatenated with k+2 gives the product of two numbers which differ by 9. %e A116175 4422608//4422610 = 6650265 * 6650274, where // denotes %e A116175 concatenation. %Y A116175 Cf. A116169, A116174, A116182, A116306. %K A116175 nonn,base %O A116175 1,1 %A A116175 _Giovanni Resta_, Feb 06 2006