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 A189480 #15 Nov 18 2013 11:03:54 %S A189480 0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0, %T A189480 1,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0, %U A189480 1,2,3,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,1,2,3,0,1,2,3,0,1,2,3,0,1,2,3,0,1,2,2,3,0,1,2,3,0 %N A189480 [4rn]-4[rn], where r=sqrt(5) and [ ]=floor. %C A189480 Suppose, in general, that a(n)=[(bn+c)r]-b[nr]-[cr]. If r>0 and b and c are integers satisfying b>=2 and 0<=c<=b-1, then 0<=a(n)<=b. The positions of 0 in the sequence a are of interest, as are the position sequences for 1,2,...,b. These b+1 (or b) position sequences comprise a partition of the positive integers. %H A189480 Ivan Panchenko, <a href="/A189480/b189480.txt">Table of n, a(n) for n = 1..1000</a> %t A189480 r=Sqrt[5]; %t A189480 f[n_]:=Floor[4 n*r]-4*Floor[n*r]; %t A189480 t=Table[f[n],{n,1,320}] (*A189480*) %t A189480 Flatten[Position[t,0]] (*A190813*) %t A189480 Flatten[Position[t,1]] (*A190883*) %t A189480 Flatten[Position[t,2]] (*A190884*) %t A189480 Flatten[Position[t,3]] (*A190885*) %Y A189480 Cf. A190813, A190883, A190884, A190885. %K A189480 nonn %O A189480 1,3 %A A189480 _Clark Kimberling_, Apr 23 2011