A179040 Number of permutations of 1..n with no three elements collinear.

1, 1, 2, 4, 18, 56, 272, 1000, 6080, 33644, 214024, 1363836, 10877964, 75783376, 648644300, 5765475224, 49406530846, 431491536076

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

Table of n, a(n) for n=0..17.

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