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 A083218 #7 May 28 2013 19:32:39
%S A083218 1,2,0,4,2,6,1,0,0,10,2,12,1,2,0,16,2,18,1,0,0,22,2,0,1,2,0,28,2,30,1,
%T A083218 0,0,4,2,36,1,2,0,40,2,42,1,0,0,46,2,0,1,2,0,52,2,0,1,0,0,58,2,60,1,2,
%U A083218 0,4,2,66,1,0,0,70,2,72,1,2,0,4,2,78,1,0,0,82,2,0,1,2,0,88,2,2,1,0,0,4,2,96
%N A083218 a(n) = n mod (spf(n+1)+1), where spf(n) is the smallest prime factor of n (A020639).
%C A083218 a(n) = n iff n+1 is prime: a(A006093(k))=A006093(k).
%H A083218 Harvey P. Dale, <a href="/A083218/b083218.txt">Table of n, a(n) for n = 1..1000</a>
%t A083218 Table[Mod[n,FactorInteger[n+1][[1,1]]+1],{n,100}] (* _Harvey P. Dale_, May 28 2013 *)
%Y A083218 Cf. A057237.
%K A083218 nonn
%O A083218 1,2
%A A083218 _Reinhard Zumkeller_, Apr 22 2003