%I A089067
%S A089067 1,3,5,13,23,51,97,207,401,825,1627,3305,6559,13215,26333,52873,105539,
%T A089067 211479,422557,845939,1691053,3383733,6765839,13534983,27066661,
%U A089067 54139881,108273203,216559621,433106027,866238387,17322450441
%N A089067 a(n) = 2*a(n-1)+(-1)^n*a([n/2]);a(1)=1.
%C A089067 a(2)=2*1+1=3; a(3)=2*3-1=5; a(4)=2*5+3=13; a(5)=2*13-3=23; a(6)=2*23+5=51; 
               a(7)=2*51-5=97; ....
%F A089067 a(n)/2^n -> 0.8067474...as n->infinity.
%Y A089067 Sequence in context: A153866 A104222 A045414 this_sequence A026733 A005824 
               A027305
%Y A089067 Adjacent sequences: A089064 A089065 A089066 this_sequence A089068 A089069 
               A089070
%K A089067 easy,nonn
%O A089067 1,2
%A A089067 DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Dec 02 2003