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 A045858 #16 Aug 09 2021 04:58:40 %S A045858 2,7,20,21,22,64,65,66,67,68,69,70,200,201,202,203,204,205,206,207, %T A045858 208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,633, %U A045858 634,635,636,637,638,639,640,641,642,643,644,645,646,647,648,649,650,651 %N A045858 Numbers whose square has initial digit '4'. %H A045858 Seiichi Manyama, <a href="/A045858/b045858.txt">Table of n, a(n) for n = 1..10000</a> %Y A045858 Cf. A045787. %K A045858 nonn,base %O A045858 1,1 %A A045858 _Jeff Burch_