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A285878
Number of possible chess games at the end of the n-th ply starting with just pawns and king.
6
1, 18, 324, 5658, 98766, 1683597, 28677387, 479763588, 8014917042, 132060434889, 2170519816231
OFFSET
0,2
COMMENTS
Gives the number of possible chess games where both sides start without queens, rooks, knights, and bishops.
Does not include games which end in fewer than n plies.
Initial terms computed using the Chesspresso engine.
LINKS
EXAMPLE
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).
CROSSREFS
Cf. A048987 (standard), A285873 (no queens), A285874 (no rooks), A285875 (no knights), A285876 (no bishops), A285877 (no pawns).
Sequence in context: A207465 A207240 A207498 * A171292 A001027 A285875
KEYWORD
nonn,hard,more,fini
AUTHOR
Sean A. Irvine, Apr 28 2017
EXTENSIONS
a(10) from Sean A. Irvine, May 04 2017
STATUS
approved