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 A112964 #7 May 13 2013 01:54:08 %S A112964 0,1,2,0,0,-6,-3,-12,-11,-13,-22,-19,-20,-30,-41,-15,-55,-24,-52,-41, %T A112964 -59,-24,-109,-22,-78,-42,-111,-26,-131,-2,-119,-75,-133,-8,-214,7, %U A112964 -175,-68,-176,-17,-209,14,-231,-73,-175,45,-349,-11,-236,-20,-236,-53,-384,68,-321,-56,-270,1,-457,41,-328,-48 %N A112964 Sum(mu(i)*sigma(j): i+j=n), with mu=A008683 and sigma=A000203. %H A112964 Charles R Greathouse IV, <a href="/A112964/b112964.txt">Table of n, a(n) for n = 1..10000</a> %e A112964 a(5)=mu(1)*sigma(4)+mu(2)*sigma(3)+mu(3)*sigma(2)+mu(4)*sigma(1) %e A112964 = 1*7 - 1*4 - 1*3 + 0*1 = 0. %o A112964 (PARI) a(n)=sum(i=1,n-1,moebius(i)*sigma(n-i)) \\ _Charles R Greathouse IV_, Feb 14 2013 %Y A112964 Cf. A024916, A000385, A068341, A112962, A112963, A112966, A112968. %K A112964 sign %O A112964 1,3 %A A112964 _Reinhard Zumkeller_, Oct 07 2005