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 A337511 #14 Sep 20 2020 21:09:30
%S A337511 1,2,1,1,2,1,2,3,3,4,5,3,4,6,4,1,5,2,2,3,4,5,6,5,7,6,7,3,8,8,7,9,6,7,
%T A337511 9,8,10,8,10,11,11,4,12,9,10,12,9,11,13,14,13,12,13,10,5,14,6,11,12,
%U A337511 15,13,15,16,16,17,17,14,14,18,7,8,15,9,18,15,16,16,17
%N A337511 A333663(n) is the a(n)-th term in A333663 with its leading digit.
%H A337511 David A. Corneth, <a href="/A337511/b337511.txt">Table of n, a(n) for n = 1..10000</a>
%e A337511 A333663 starts 1, 16, 64, 4, 49, 9, 900, 961, 100, ... so
%e A337511 A333663(1) is the first term with a leading 1 giving a(1) = 1.
%e A337511 A333663(2) is the second term with a leading 1 so a(2) = 2.
%e A337511 A333663(3) is the first term with a leading 6 so a(3) = 1.
%t A337511 With[{t = Map[IntegerDigits[#][[1]] &, Nest[Block[{a = #, k = 1, d = Mod[#[[-1]]/10^IntegerExponent[#[[-1]] ], 10]}, While[Nand[FreeQ[a, #], d == Floor[#/10^(IntegerLength[#] - 1)] ] &[k^2], k++]; Append[a, k^2]] &, {1}, 77]]}, Array[Count[t[[1 ;; #]], t[[#]]] &, Length[t]]] (* _Michael De Vlieger_, Sep 11 2020 *)
%Y A337511 Cf. A333663.
%K A337511 nonn,easy,base
%O A337511 1,2
%A A337511 _David A. Corneth_, Sep 07 2020