Number of permutations p of 1,2,...,n satisfying |p(i+1)-p(i)|<>3 and |p(j+3)-p(j)|<>1 for all i=1..n-1, j=1..n-3.
A189358
Number of permutations p of 1,2,...,n satisfying |p(i+1)-p(i)|<>3 and |p(j+3)-p(j)|<>1 for all i=1..n-1, j=1..n-3.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =8a(5) =24a(6) =126a(7) =524a(8) =3072a(9) =22854a(10) =189646a(11) =1827114a(12) =19889946a(13) =238648524a(14) =3131979014a(15) =44540692612a(16) =681114241416
External references
- oeis: A189358