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

A179040

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

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =18a(5) =56a(6) =272a(7) =1000a(8) =6080a(9) =33644a(10) =214024a(11) =1363836a(12) =10877964a(13) =75783376a(14) =648644300a(15) =5765475224a(16) =49406530846a(17) =431491536076

External references