%I
%S 0,1,2,5,10,24,50,121,260,637,1400,3468,7752,19380,43890,110561,
%T 253000,641355,1480050,3771885,8765250,22439040,52451256,134796060,
%U 316663760,816540124,1926501200,4982228488,11798983280,30593078076,72690164850
%N Sum of lists created by n substitutions k > Range[k+1,0,2] starting with {0}, counting down from k+1 to 0 step 2.
%C Lengths of lists is A047749.
%F Equals A093951(n)A047749(n).
%e lists {0}, {1}, {2, 0}, {3, 1, 1}, {4, 2, 0, 2, 0, 2, 0}
%e sum to 0, 1, 2, 5, 10
%t Plus@@@Flatten/@NestList[ # /. k_Integer :> Range[k+1, 0, 2]&, {0}, 8]
%Y Cf. A047749.
%Y Cf. A093951, A047749.
%K nonn
%O 0,3
%A _Wouter Meeussen_, May 11 2003
