Number of permutations p of 1,2,...,n satisfying |p(i+1)-p(i)|<>4 and |p(j+4)-p(j)|<>1 for all i=1..n-1, j=1..n-4.
A189563
Number of permutations p of 1,2,...,n satisfying |p(i+1)-p(i)|<>4 and |p(j+4)-p(j)|<>1 for all i=1..n-1, j=1..n-4.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =48a(6) =182a(7) =868a(8) =5752a(9) =37156a(10) =296944a(11) =2738820a(12) =28894206a(13) =335399468a(14) =4285522402a(15) =59536763892a(16) =892785282788
External references
- oeis: A189563