Number of permutations p of 1,2,...,n satisfying |p(i+3)-p(i)|<>4 and |p(j+4)-p(j)|<>3 for all i=1..n-3, j=1..n-4.
A189568
Number of permutations p of 1,2,...,n satisfying |p(i+3)-p(i)|<>4 and |p(j+4)-p(j)|<>3 for all i=1..n-3, j=1..n-4.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =80a(6) =326a(7) =1566a(8) =9544a(9) =65036a(10) =518498a(11) =4750006a(12) =48830634a(13) =554929274a(14) =6926227324a(15) =93970452970
External references
- oeis: A189568