%I A052207
%S A052207 0,0,0,0,0,8,16,40,80,168,336,672,1344,2640,5280,10296,20592,40040,
%T A052207 80080,155584,311168,604656,1209312,2351440
%N A052207 Number of {s(i):i=0..n} such that |s(i)-s(i-1)|=1, i=1..n and s(i)=0 
               at four values of i, one of which is i=0.
%C A052207 Calculation suggests that {a(2n)/8} is A002054 (shifted).
%Y A052207 Sequence in context: A024700 A108576 A108235 this_sequence A038578 A155110 
               A022444
%Y A052207 Adjacent sequences: A052204 A052205 A052206 this_sequence A052208 A052209 
               A052210
%K A052207 nonn
%O A052207 1,6
%A A052207 John W. Layman (layman(AT)math.vt.edu), Jan 26 2000