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%I #11 May 04 2017 15:02:19
%S 1,18,324,5658,98766,1683597,28677387,479763588,8014917042,
%T 132060434889,2170519816231
%N Number of possible chess games at the end of the n-th ply starting with just pawns and king.
%C Gives the number of possible chess games where both sides start without queens, rooks, knights, and bishops.
%C Does not include games which end in fewer than n plies.
%C Initial terms computed using the Chesspresso engine.
%H Bernhard Seybold, <a href="http://www.chesspresso.org/">Chesspresso</a>.
%e a(1) = 18 since each pawn can move forward 1 or 2 squares (16 moves) or the king can move left or right (2 moves).
%Y Cf. A048987 (standard), A285873 (no queens), A285874 (no rooks), A285875 (no knights), A285876 (no bishops), A285877 (no pawns).
%K nonn,hard,more,fini
%O 0,2
%A _Sean A. Irvine_, Apr 28 2017
%E a(10) from _Sean A. Irvine_, May 04 2017