Number of permutations p of 1,2,...,n satisfying p(i+3)-p(i)<>3 for all 1<=i<=n-3.

A189282

Number of permutations p of 1,2,...,n satisfying p(i+3)-p(i)<>3 for all 1<=i<=n-3.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =22a(5) =98a(6) =534a(7) =3414a(8) =25498a(9) =217338a(10) =2080990a(11) =22076030a(12) =256888218a(13) =3252308706a(14) =44497313158a(15) =654139144158

External references