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 A115445 #5 Jun 18 2021 18:09:45 %S A115445 9,13,3656545,4565636,5434365,6343456,3646962589704198389, %T A115445 6353037410295801612,9101508044249652935, %U A115445 7903999111431765764698711045778,9722180929613583946516892863960 %N A115445 Numbers whose square is the concatenation of two numbers k and k-7. %e A115445 4023943_4023936 = 6343456^2. %Y A115445 Cf. A030467, A106497, A115434, A115427, A115438, A115439, A115440, A115441, A115442, A115443, A115444, A115446, A115447. %K A115445 base,nonn %O A115445 1,1 %A A115445 _Giovanni Resta_, Jan 25 2006