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 A168393 #2 Mar 31 2012 10:24:25 %S A168393 0,1,0,0,1,0,1,1,-1,1,1,-1,0,0,0,0,0,1,0,0,0,1,1,0,-1,-1,0,1,0,1,1,-1, %T A168393 0,0,-1,0,-1,-1,0,0,-1,0,-1,0,1,1,0,0,-1,0,0,-1,1,0,-1,0,1,0,-1,0,0,1, %U A168393 0,0,0,1,0,0,0,0,0,-1,0,1,1,1,-1,0,0,0,-1,0,0,0,1,1,0,1,-1,1,-1,1,0,1,-1,1 %N A168393 Moebius function of interprimes (A024675). %p A168393 ts_fip:=proc(n) local i,an: an:=[ ]: for i from 2 to n do an:=[ op(an), numtheory[mobius]((ithprime(i)+ithprime(i+1))/2) ]: od: RETURN(an) end: ts_fip(500); %Y A168393 Cf. A008683. %K A168393 sign %O A168393 1,1 %A A168393 _Jani Melik_, Nov 24 2009