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 A045861 #23 Aug 09 2021 04:57:59
%S A045861 27,28,84,85,86,87,88,89,265,266,267,268,269,270,271,272,273,274,275,
%T A045861 276,277,278,279,280,281,282,837,838,839,840,841,842,843,844,845,846,
%U A045861 847,848,849,850,851,852,853,854,855,856,857,858,859,860,861,862,863
%N A045861 Numbers whose square has initial digit '7'.
%H A045861 Seiichi Manyama, <a href="/A045861/b045861.txt">Table of n, a(n) for n = 1..10000</a>
%t A045861 Flatten[Table[Range[Ceiling[Sqrt[7 10^i]],Floor[Sqrt[8 10^i-1]]],{i,2,5}]] (* _Harvey P. Dale_, Mar 06 2011 *)
%Y A045861 Cf. A045791.
%K A045861 nonn,base
%O A045861 1,1
%A A045861 _Jeff Burch_