%I #2 Mar 30 2012 18:51:51
%S 0,1,-1,0,0,2,-3,1,0,3,-5,2,0,4,-7,3,0,5,-9,4,0,6,-11,5,0,7,-13,6,0,8,
%T -15,7,0,9,-17,8,0,10,-19,9,0,11,-21,10,0,12,-23,11,0,13,-25,12,0,14,
%U -27,13,0,15,-29,14,0,16,-31,15,0,17,-33,16,0,18,-35,17,0,19,-37,18,0,20,-39,19,0,21,-41,20
%N Second differences of A130845.
%K sign
%O 0,6
%A _Paul Curtz_, Aug 16 2007