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 A048351 #34 Mar 06 2025 10:49:27
%S A048351 4,26,216,1291,5164,68313,163284,785294,3559026,26393686,129099069,
%T A048351 254296413,816435342,4081257976,80413106314,215329205326,
%U A048351 2463064689907,5165911014784,24832773982716,81401883640163,752766125152206,4086159158264236,21602469586893686,32659863237109026,683788466294121304
%N A048351 a(n)^2 is the smallest square containing exactly n 6's.
%H A048351 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SquareNumber.html">Square Number</a>
%F A048351 a(n) = sqrt(A036513(n)).
%t A048351 a[n_] := Module[{i = 1}, While[DigitCount[i^2][[6]] != n, i++;]; i]; (* Sam Handler (sam_5_5_5_0(AT)yahoo.com), Aug 20 2006 *)
%o A048351 (Python)
%o A048351 def a(n):
%o A048351 k = 1
%o A048351 while not str(k**2).count('6') == n: k += 1
%o A048351 return k
%o A048351 print([a(n) for n in range(1, 11)]) # _Michael S. Branicky_, Apr 26 2021
%Y A048351 Cf. A036513, A034988.
%K A048351 nonn,base
%O A048351 1,1
%A A048351 _Patrick De Geest_, Mar 15 1999
%E A048351 a(13) from Sam Handler (sam_5_5_5_0(AT)yahoo.com), Aug 20 2006
%E A048351 a(14)-a(15) from _Jon E. Schoenfield_, Jan 14 2009
%E A048351 a(16) from _Jon E. Schoenfield_, Jan 24 2009
%E A048351 a(17)-a(20) from _Giovanni Resta_, Jul 27 2018
%E A048351 a(21)-a(25) from _Max Alekseyev_, Mar 06 2025