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%I #5 Mar 30 2012 18:37:43
%S 1,2,4,9,19,44,96,227,507,1218,2768,6732,15504,38076,88616,219351,
%T 514855,1282710,3031860,7594665
%N Length of lists created by n substitutions k -> Range[k+1,-Abs[k],-2] starting with {1}.
%e {1}, {2,0}, {3,1,-1,1}, {4,2,0,-2,2,0,0,2,0} have lengths 1, 2, 4, 9.
%t Length/@Flatten/@NestList[ # /. k_Integer:>Range[k+1, -Abs[k], -2]&, {1}, 16]
%K nonn
%O 0,2
%A _Wouter Meeussen_, May 11 2003
%E a(17)-a(19) from _Robert G. Wilson v_, Aug 17 2009
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