%I #1 Jun 12 2004 03:00:00
%S 1,2,4,21,55,151,447,1389,4502,15046,51505,179463,634086,2265014,
%T 8163125,29637903,108282989,397761507,1468063369,5441174511,
%U 20242989728,75566702558,282959337159,1062523000005,4000108867555,15095081362907,57088782570433
%N Erroneous version of A005217.
%K dead
%O 1,2