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 A113048 #4 Mar 18 2018 17:50:40
%S A113048 1,1,0,2,0,1,0,0,0,0,0,2,0,2,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,
%T A113048 0,0,0,0,0,0,0,0,0,2,0,2,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U A113048 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N A113048 Binomial(4n,n)/(3n+1) mod 4.
%C A113048 It would appear that the behavior of this sequence is determined by values of the Jacobsthal numbers J(n)=A001045(n): a(n)=1 only if n=J(2k),k=0,1,...; a(n)=2 only if n=J(2k+3)+2J(2j), some k,j>=0, otherwise a(n)=0.
%t A113048 Table[Mod[Binomial[4n,n]/(3n+1),4],{n,0,120}] (* _Harvey P. Dale_, Mar 18 2018 *)
%Y A113048 Cf. A039969, A113047, A113049.
%K A113048 easy,nonn
%O A113048 0,4
%A A113048 _Paul Barry_, Oct 11 2005