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 A116104 #12 Sep 14 2023 00:46:21 %S A116104 65,6653,9605,218413,283720,996005,58446925,99960005,6086712229, %T A116104 7385370133,8478948853,9999600005,120178240093,161171620229, %U A116104 358247912200,426843573160,893417179213,999996000005,23376713203604 %N A116104 Numbers k such that k concatenated with k-8 gives the product of two numbers which differ by 4. %C A116104 Duplicate of A115432. See proof at A115432. - _Robert Israel_, Sep 13 2023 %e A116104 9999600005//9999599997 = 9999799999 * 9999800003, where // denotes concatenation. %Y A116104 Cf. A116096, A116103, A116105, A115431, A116235. %K A116104 nonn,base %O A116104 1,1 %A A116104 _Giovanni Resta_, Feb 06 2006