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%I #2 Mar 30 2012 16:51:55
%S 2,20,188,1222,6872,35954,180070
%N Total number of balls in room in variant of the tennis ball problem (cf. A171074);
%C Apparently equals A051133(n) - A090288(n-1) after 1st term.
%C Note that A051133 yields the totals of all C(2n, n) ball sets and A005893 and A090288 are the respective totals of impossible combinations given the rules.
%D David Scambler, Just for fun, more tennis balls, Posting to the Sequence Fans Mailing List, Aug 25 2010.
%K nonn
%O 1,1
%A _N. J. A. Sloane_, Sep 06 2010