Number of permutations of length n with no consecutive triples i,...i+r,...i+2r for all positive and negative r, and for all equal spacings d.

A174085

Number of permutations of length n with no consecutive triples i,...i+r,...i+2r for all positive and negative r, and for all equal spacings d.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =18a(5) =72a(6) =396a(7) =2328a(8) =17050a(9) =131764a(10) =1199368a(11) =11379524a(12) =123012492a(13) =1386127700a(14) =17450444866a(15) =227152227940

External references