%I A033623
%S A033623 1,2,4,8,15,16,32,51,64,85,106,128,150,171,219,237,247,256,279,297,
%T A033623 455,512,537,557,594,643,803,863,998,1024,1051,1070,1112,1169,1333,
%U A033623 1345,1620,1866,2048,2076,2085,2185,2372
%N A033623 Grundy function for turn-at-most-4-coins game.
%D A033623 E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Table 3, page 
               433.
%F A033623 a(n)=smallest natural not the exclusive-or of at most three a(k) for 
               k<n.
%Y A033623 Cf. A000069, A054016, A054043, etc.
%Y A033623 Sequence in context: A140117 A039743 A070008 this_sequence A094398 A026474 
               A082562
%Y A033623 Adjacent sequences: A033620 A033621 A033622 this_sequence A033624 A033625 
               A033626
%K A033623 nonn,nice,easy
%O A033623 1,2
%A A033623 David A. Madore (david.madore(AT)ens.fr)
%E A033623 More terms from N. J. A. Sloane (njas(AT)research.att.com) Apr 29, 2000