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 A115444 #5 Jun 18 2021 18:16:10 %S A115444 46,55,949951,979654,7771781679,7900890080,9920892100,9949999501, %T A115444 38773083432317,41534158410842,47433813119408,52566186880593, %U A115444 58465841589159,61226916567684,72258945037435,86156896546725 %N A115444 Numbers whose square is the concatenation of two numbers k and k-5. %e A115444 902406_902401 = 949951^2. %Y A115444 Cf. A030467, A106497, A115433, A115427, A115438, A115439, A115440, A115441, A115442, A115443, A115445, A115446, A115447. %K A115444 base,nonn %O A115444 1,1 %A A115444 _Giovanni Resta_, Jan 25 2006