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 A048348 #22 Mar 06 2025 10:43:42
%S A048348 6,56,586,1156,11547,57735,559769,1197219,6582806,36514844,350903624,
%T A048348 1798230611,1825769244,48304278624,11547014044,577333277556,
%U A048348 1527394295306,6582576498844,57465931849517,416333244448889,581664313273844,4820096824065156,18256870415638994,61913999493598646,577694870440557344
%N A048348 a(n)^2 is the smallest square containing exactly n 3's.
%H A048348 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SquareNumber.html">Square Number</a>
%t A048348 a[n_] := Block[{k=1}, While[DigitCount[k^2, 10, 3] != n, k++]; k]; Array[a, 6] (* _Giovanni Resta_, Jul 27 2018 *)
%Y A048348 Cf. A036510, A034982.
%K A048348 nonn,base
%O A048348 1,1
%A A048348 _Patrick De Geest_, Mar 15 1999
%E A048348 More terms from _Jon E. Schoenfield_, Jan 11 2009
%E A048348 a(18)-a(19) from _Giovanni Resta_, Jul 27 2018
%E A048348 a(20)-a(25) from _Max Alekseyev_, Mar 06 2025