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 A115229 Number of ways in chess to force mate in n moves for a single knight against a single pawn, without duals, without short mates and excluding rotations, mirroring and color reversing. 0
 3, 12, 16, 31, 21, 44, 3, 6 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS The mate is only possible against a pawn on a border line (a-line or h-line). No non-dual (single solution) mates are possible beyond n = 7 (cf. Springerzauber, page 178). Obviously the positions with the higher number of moves lead via a unique chain of positions with the lower numbers. REFERENCES John Selman and Harrie Grondijs, Springerzauber, 1998, chapter 16. LINKS EXAMPLE Example: The three positions with 0 moves (checkmate) are: a) White: Kc2, Nb3, Black: Ka1, Pawn a2 b) White: Kc1, Nb3, Black: Ka1, Pawn a2 c) White: Kc1, Nc2, Black: Ka1, pawn a2 CROSSREFS Sequence in context: A277738 A064106 A022411 * A224924 A136047 A082965 Adjacent sequences: A115226 A115227 A115228 * A115230 A115231 A115232 KEYWORD nonn AUTHOR N. J. A. Sloane, based on email from Harrie Grondijs, Mar 06 2006 STATUS approved

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Last modified December 9 18:21 EST 2022. Contains 358703 sequences. (Running on oeis4.)