%I A105811
%S A105811 1,1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,
%T A105811 25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,
%U A105811 48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65
%V A105811 1,-1,0,1,-2,3,-4,5,-6,7,-8,9,-10,11,-12,13,-14,15,-16,17,-18,19,-20,21,
               -22,23,-24,25,
%W A105811 -26,27,-28,29,-30,31,-32,33,-34,35,-36,37,-38,39,-40,41,-42,43,-44,45,
               -46,47,-48,49,
%X A105811 -50,51,-52,53,-54,55,-56,57,-58,59,-60,61,-62,63,-64,65
%N A105811 Expansion of (1+x-x^2)/(1+x)^2.
%C A105811 First column of number triangle A105810.
%F A105811 a(n)=-0^n-(-1)^n*(n-2)
%Y A105811 Sequence in context: A097141 A160356 A038608 this_sequence A069782 A088480 
               A061019
%Y A105811 Adjacent sequences: A105808 A105809 A105810 this_sequence A105812 A105813 
               A105814
%K A105811 easy,sign
%O A105811 0,5
%A A105811 Paul Barry (pbarry(AT)wit.ie), May 04 2005