%I A140721
%S A140721 1,7,4,28,16,112,64,448,256,1792,1024,7168,4096,28672,16384,114688,
%T A140721 65536,458752,262144,1835008,1048576,7340032,4194304,29360128,16777216,
%U A140721 117440512,67108864,469762048,268435456,1879048192,1073741824
%V A140721 1,-7,4,-28,16,-112,64,-448,256,-1792,1024,-7168,4096,-28672,16384,-114688,
               65536,
%W A140721 -458752,262144,-1835008,1048576,-7340032,4194304,-29360128,16777216,-117440512,
%X A140721 67108864,-469762048,268435456,-1879048192,1073741824
%N A140721 Alternated reading of A000302 and negated A002042.
%C A140721 Sequence can also be obtained by negating the first differences of A135520: 
               a(n)=A135520(n)-A135520(n+1).
%F A140721 a(2n) = A000302(n). a(2n+1) = -A002042(n) .
%F A140721 a(2n) = -7a(2n-1). a(2n)-a(2n-1) = A002089(n-1). a(n)+a(n+1) = -3*A135520(n).
%F A140721 O.g.f.: (7x-1)/((2x-1)(2x+1)). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Jul 14 2008
%Y A140721 Sequence in context: A075536 A085047 A070427 this_sequence A038270 A100976 
               A152627
%Y A140721 Adjacent sequences: A140718 A140719 A140720 this_sequence A140722 A140723 
               A140724
%K A140721 sign,less
%O A140721 0,2
%A A140721 Paul Curtz (bpcrtz(AT)free.fr), Jul 12 2008
%E A140721 Edited by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 14 2008