%I A077973
%S A077973 1,1,1,1,3,5,3,3,13,19,13,13,51,77,51,51,205,307,205,205,819,1229,819,
               819,
%T A077973 3277,4915,3277,3277,13107,19661,13107,13107,52429,78643,52429,52429,209715,
%U A077973 314573,209715,209715,838861,1258291,838861,838861,3355443,5033165,3355443
%V A077973 1,-1,1,1,-3,5,-3,-3,13,-19,13,13,-51,77,-51,-51,205,-307,205,205,-819,
               1229,-819,-819,
%W A077973 3277,-4915,3277,3277,-13107,19661,-13107,-13107,52429,-78643,52429,52429,
               -209715,
%X A077973 314573,-209715,-209715,838861,-1258291,838861,838861,-3355443,5033165,
               -3355443
%N A077973 Expansion of 1/(1+x-2*x^3).
%C A077973 Essentially the same as A077950.
%F A077973 a(n)=-a(n-1)+2a(n-3). - Paul Curtz (bpcrtz(AT)free.fr), Apr 23 2008
%Y A077973 Sequence in context: A133773 A077934 A077950 this_sequence A010703 A107489 
               A152050
%Y A077973 Adjacent sequences: A077970 A077971 A077972 this_sequence A077974 A077975 
               A077976
%K A077973 sign
%O A077973 0,5
%A A077973 N. J. A. Sloane (njas(AT)research.att.com), Nov 17 2002, Jun 17 2007