Number of permutations p of 1,2,...,n satisfying |p(i+2)-p(i)|<>5 and |p(j+5)-p(j)|<>2 for all i=1..n-2, j=1..n-5.

A189567

Number of permutations p of 1,2,...,n satisfying |p(i+2)-p(i)|<>5 and |p(j+5)-p(j)|<>2 for all i=1..n-2, j=1..n-5.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =120a(6) =392a(7) =1810a(8) =10400a(9) =72228a(10) =589674a(11) =5196870a(12) =52398658a(13) =588036216a(14) =7274466172a(15) =98024173852

External references