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 A353060 Solution to Snake Numbers Problems from 1 to n for an n X n square grid with chess knight moves (see Comments). 3
 1, 1, 3, 13, 15, 36, 39, 64 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS On an n X n square board we draw a path with squares that we number 1, 2, ..., n, 1, 2, ..., n, 1, ... of the greatest length, which will be a(n). The path advances from one number to the next with a knight move; after n it goes back to number 1. There cannot be repeated numbers in the same row or column. LINKS Table of n, a(n) for n=1..8. Rodolfo Kurchan, Puzzle Fun, Snake Number Problem EXAMPLE a(5) = 15 by Rodolfo Kurchan: +---+---+---+---+---+ | | 04| 12| | | +---+---+---+---+---+ | | | | 05| 13| +---+---+---+---+---+ | 03| 11| 14| 22| 25| +---+---+---+---+---+ | 15| 23| | 01| | +---+---+---+---+---+ | | 02| 21| 24| | +---+---+---+---+---+ First digit of the 2 digits number indicates the order of the path, second digit indicates the number of the "snake" path that cannot be repeated in same row or column. In case of a(5) it is 01, 02, 03, 04, 05, 11, 12, 13, 14, 15, 21, 22, 23, 24, 25 and then it is impossible go to 31 because number 1 will be repeated in the row or column. a(6), a(7) and a(8) solutions found by computer from Giorgio Vecchi. CROSSREFS Cf. A353259. Sequence in context: A032623 A146512 A082704 * A152270 A032919 A340018 Adjacent sequences: A353057 A353058 A353059 * A353061 A353062 A353063 KEYWORD nonn,more AUTHOR Rodolfo Kurchan, Apr 20 2022 STATUS approved

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Last modified September 22 13:35 EDT 2023. Contains 365531 sequences. (Running on oeis4.)