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 A115533 #5 Jul 15 2021 06:29:39 %S A115533 24489796,55102041,97959184,15976331361,28402366864,44378698225, %T A115533 63905325444,86982248521, %U A115533 24489795918367346938775510204081632653061224489796 %N A115533 Numbers k such that the concatenation of 3*k with k gives a square. %e A115533 73469388_24489796 = 85714286^2. %Y A115533 Cf. A102567, A106497, A115527 - A115556. %K A115533 nonn,base %O A115533 1,1 %A A115533 _Giovanni Resta_, Jan 25 2006