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 A048346 #25 Mar 06 2025 10:53:25
%S A048346 0,1,11,109,1054,3381,10541,105414,414139,1055041,10252371,78173596,
%T A048346 334082481,1187901979,1055036071,33333407869,105409293239,
%U A048346 718412219489,1054501356619,10536182856619,105409445099152,333331983425106,1054092079569499,10541257568071331,37564758898655414,33333331983425106
%N A048346 a(n)^2 is the smallest square containing exactly n 1's in its decimal notation.
%H A048346 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SquareNumber.html">Square Number</a>
%t A048346 a[n_] := Block[{k=0}, While[DigitCount[k^2, 10, 1] != n, k++]; k]; Array[a, 8, 0] (* _Giovanni Resta_, Jul 27 2018 *)
%Y A048346 Cf. A036508, A034978.
%K A048346 nonn,base
%O A048346 0,3
%A A048346 _Patrick De Geest_, Mar 15 1999
%E A048346 More terms from _Jon E. Schoenfield_, Jan 11 2009
%E A048346 Initial zero added by _Zak Seidov_, Nov 22 2010
%E A048346 a(17)-a(19) from _Giovanni Resta_, Jul 27 2018
%E A048346 a(20)-a(25) from _Max Alekseyev_, Mar 06 2025