%I #21 Oct 18 2018 04:57:45
%S 1,4,22,1474
%N Number of normal play partisan games born on or before day n.
%C Fraser and Wolfe prove upper and lower bounds on a(n+1) in terms of a(n). In particular they give the (probably quite weak) lower bound of 3*10^12 for a(4). - _Christopher E. Thompson_, Aug 06 2015
%D Dan Calistrate, Marc Paulhus and David Wolfe, On the lattice structure of finite games, in More Games of No Chance (Berkeley, CA, 2000), Math. Sci. Res. Inst. Publ., 42, Cambridge Univ. Press, Cambridge, 2002, pp. 25-30.
%D J. H. Conway, On Numbers and Games, Academic Press, NY, 1976.
%D Aaron N. Siegel, Combinatorial Game Theory, AMS Graduate Texts in Mathematics Vol 146 (2013), p. 158.
%H William E. Fraser and David Wolfe, <a href="http://dx.doi.org/10.1016/j.tcs.2003.05.001">Counting the number of games</a>, Theoret. Comput. Sci. 313 (2004), pp. 527-532.
%F a(n) = A125990(2*A114561(n)). - _Antti Karttunen_, Oct 18 2018
%Y Cf. A065402, A065407, A047995, A037142, A114561, A125990, A126011.
%K nonn,hard,more
%O 0,2
%A _R. K. Guy_, Nov 23 2001
%E _Dean Hickerson_ and Robert Li found a(3) in 1974.