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 A204999 #12 Sep 29 2018 18:41:23
%S A204999 3,4,1,2,1,2,1,1,1,2,1,1,1,2,1,1,1,4,1,1,1,2,1,1,3,2,1,1,1,2,1,1,1,2,
%T A204999 1,2,1,2,1,1,1,2,1,1,1,2,1,1,3,4,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,2,1,1,
%U A204999 1,2,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,2,1,1,1,4,1,2,1,2,1,1,1
%N A204999 a(n) = (1/n)*A204998(n).
%C A204999 For a guide to related sequences, see A204892.
%C A204999 Positions of 3's seem to be given by a subsequence of A104777. - _Antti Karttunen_, Sep 29 2018
%H A204999 Antti Karttunen, <a href="/A204999/b204999.txt">Table of n, a(n) for n = 1..23005</a>
%F A204999 a(n) = (A204996(n)-A204997(n))/n.
%t A204999 (See the program at A204994.)
%o A204999 (PARI) A204999(n) = { my(d); for(k=sqrtint(1+n), oo, for(j=1,k-1,if(!((d=(k^2)-(j^2))%n),return(d/n),if(d<n,break)))); }; \\ _Antti Karttunen_, Sep 28 2018
%Y A204999 Cf. A204996, A204997, A204998, A204892.
%K A204999 nonn
%O A204999 1,1
%A A204999 _Clark Kimberling_, Jan 21 2012
%E A204999 More terms from _Antti Karttunen_, Sep 28 2018