Number of permutations p of 1,2,...,n satisfying p(i+4)-p(i)<>4 for all 1<=i<=n-4.

A189283

Number of permutations p of 1,2,...,n satisfying p(i+4)-p(i)<>4 for all 1<=i<=n-4.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =114a(6) =628a(7) =4062a(8) =30360a(9) =255186a(10) =2414292a(11) =25350954a(12) =292378968a(13) =3673917102a(14) =49928069188a(15) =729534877758

External references