Urban Larsson

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The P-positions of the well-known 2-pile takeaway game of Wythoff Nim lie on two 'beams' of slope √ 5+1 2 and √ 5−1 2 respectively. We study extensions to this game where a player may also remove simultaneously pt tokens from either of the piles and qt from the other, where p < q are given positive integers and where t ranges over the positive integers. We(More)
We study a variation of the combinatorial game of 2-pile Nim. Move as in 2-pile Nim but with the following constraint: Provided the previous player has just removed say x > 0 tokens from the pile with less tokens, the next player may remove x tokens from the pile with more tokens. But for each move, in " a strict sequence of previous player-next player(More)
The 2-player impartial game of Wythoff Nim is played on two piles of tokens. A move consists in removing any number of tokens from precisely one of the piles or the same number of tokens from both piles. The winner is the player who removes the last token. We study this game with a blocking maneuver, that is, for each move, before the next player moves the(More)
We study so-called invariant games played with a fixed number d of heaps of matches. A game is described by a finite list M of integer vectors of length d specifying the legal moves. A move consists in changing the current game-state by adding one of the vectors in M, provided all elements of the resulting vector are nonnegative. For instance, in a two-heap(More)
We study 2-player impartial games of the form takeaway which produce P-positions (second player winning positions) corresponding to so-called complementary Beatty sequences, given by the continued Our problem is the opposite of the main field of research in this area, which is to, given a game, understand its set of P-positions. We are rather given a set of(More)
One single Queen is placed on an arbitrary starting position of a (large) Chess board. Two players alternate in moving the Queen as in a game of Chess but with the restriction that the L 1 distance to the lower left corner, position (0, 0), must decrease. The player who moves there wins. Let φ = 1+ √ 5 2 , the golden ratio. In 1907 W. A. Wythoff proved that(More)