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 A116205 #12 Jul 19 2021 01:56:07 %S A116205 1,81,1353,3997,7723,23761,26271,76771,1415683,3890571,8495497, %T A116205 1066870443,1239366513,4198438981,4534273891,6502317141,6918679731, %U A116205 2199164200036329043,2820114781174460091,5500888421709400741 %N A116205 Numbers k such that k concatenated with k+7 gives the product of two numbers which differ by 3. %C A116205 Also numbers k such that k concatenated with k+9 gives the product of two numbers which differ by 1. %C A116205 Also numbers k such that k concatenated with k-3 gives the product of two numbers which differ by 7. %Y A116205 Cf. A116179, A116172, A115429, A116173, A116193, A116336. %Y A116205 Cf. A116132, A116099, A116139, A116152, A116269, A116348. %K A116205 nonn,base %O A116205 1,2 %A A116205 _Giovanni Resta_, Feb 06 2006 %E A116205 Edited by _N. J. A. Sloane_, Apr 13 2007