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 A179040 Number of permutations of 1..n with no three elements collinear. 4
 1, 1, 2, 4, 18, 56, 272, 1000, 6080, 33644, 214024, 1363836, 10877964, 75783376, 648644300, 5765475224, 49406530846, 431491536076 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Number of permutations of 1..n with no three points (i,p(i)) (j,p(j)) (k,p(k)) collinear, or number of n X n permutation matrices with no three 1's collinear. LINKS Dániel T. Nagy, Zoltán Lóránt Nagy, and Russ Woodroofe, The extensible No-Three-In-Line problem, arXiv:2209.01447 [math.CO], 2022. CROSSREFS For "collinear modulo n" see A135538 and A146558. Sequence in context: A330432 A317887 A083694 * A241685 A009679 A007727 Adjacent sequences: A179037 A179038 A179039 * A179041 A179042 A179043 KEYWORD nonn AUTHOR R. H. Hardin, including comments and references from R. J. Mathar, Max Alekseyev and Franklin T. Adams-Watters in the Sequence Fans Mailing List, Jun 25 2010 EXTENSIONS a(0)=1 prepended by Alois P. Heinz, Sep 14 2022 STATUS approved

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Last modified December 9 10:59 EST 2022. Contains 358700 sequences. (Running on oeis4.)