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 A035069 #13 Oct 08 2019 15:49:17
%S A035069 5,15,45,142,448,1415,4473,14143,44722,141422,447214,1414214,4472136,
%T A035069 14142136,44721360,141421357,447213596,1414213563,4472135955,
%U A035069 14142135624,44721359550,141421356238,447213595500,1414213562374
%N A035069 a(n) is root of square starting with digit 2: first term of runs.
%F A035069 a(n) = ceiling(sqrt(2*10^n)).
%t A035069 Table[Ceiling @ Sqrt[2 * 10^n], {n, 1, 24}] (* _Amiram Eldar_, Oct 08 2019 *)
%Y A035069 Cf. A067472 (squares), A035076 (2..9).
%K A035069 nonn,base
%O A035069 1,1
%A A035069 _Patrick De Geest_, Nov 15 1998
%E A035069 Offset 1 from _Michel Marcus_, Oct 08 2019