cp's OEIS Frontend

A213675 a(n) = Chowla's function(n) + anti-Chowla's function(n).

%I A213675 #14 Mar 15 2013 04:53:58
%S A213675 0,0,0,2,2,5,5,9,5,14,5,20,10,16,16,17,17,36,5,32,18,34,19,42,27,22,
%T A213675 36,54,5,57,21,67,40,26,41,62,25,66,42,77,14,91,27,50,88,52,29,99,46,
%U A213675 89,28,104,53,81,53,82,58,88,51,174,16,70,110,65,59,119,87,124,34,128
%N A213675 a(n) = Chowla's function(n) + anti-Chowla's function(n).
%C A213675 See A216982 for definition of anti-Chowla's function.
%F A213675 a(n) = A048050(n) + A216982(n).
%p A213675 A213675 := proc(n)
%p A213675     A048050(n)+A216982(n) ;
%p A213675 end proc; # _R. J. Mathar_, Mar 15 2013
%o A213675 (PARI) a(n)=if(n<4,0,my(k=valuation(n,2));sigma(n)+sigma(2*n+1)+sigma(2*n-1)+sigma(n>>k)<<(k+1)-3-23*n\/3) \\ _Charles R Greathouse IV_, Mar 05 2013
%K A213675 nonn,less
%O A213675 1,4
%A A213675 _Juri-Stepan Gerasimov_, Mar 04 2013
%E A213675 a(16) corrected by _Charles R Greathouse IV_, Mar 05 2013