%I A130472
%S A130472 0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14,15,
%T A130472 15,16,16,17,17,18,18,19,19,20,20,21,21,22,22,23,23,24,24,25,25,26,26,
%U A130472 27,27,28,28,29,29,30,30,31,31,32,32
%V A130472 0,-1,1,-2,2,-3,3,-4,4,-5,5,-6,6,-7,7,-8,8,-9,9,-10,10,-11,11,-12,12,-13,
               13,-14,14,-15,
%W A130472 15,-16,16,-17,17,-18,18,-19,19,-20,20,-21,21,-22,22,-23,23,-24,24,-25,
               25,-26,26,-27,
%X A130472 27,-28,28,-29,29,-30,30,-31,31,-32,32
%N A130472 A permutation of the integers: a(n)=((-1)^n)*floor((n+1)/2).
%F A130472 a(n)=-A001057(n); a(2n)=n, a(2n+1)=-n-1; a(n)=sum{k*(-1)^k: k=0,1,...,
               n}; a(n)=-a(n-1)+a(n-2)+a(n-3).
%Y A130472 Cf. A001057.
%Y A130472 Sequence in context: A127365 A065033 A001057 this_sequence A004526 A140106 
               A123108
%Y A130472 Adjacent sequences: A130469 A130470 A130471 this_sequence A130473 A130474 
               A130475
%K A130472 sign
%O A130472 0,4
%A A130472 Clark Kimberling (ck6(AT)evansville.edu), May 28 2007