Number of permutations of [n] allowing i->i+j (mod n), j=0..ceiling(n/2)-1.

A306738

Number of permutations of [n] allowing i->i+j (mod n), j=0..ceiling(n/2)-1.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =13a(6) =20a(7) =144a(8) =264a(9) =2783a(10) =6208a(11) =79118a(12) =204448a(13) =3182225a(14) =9411840a(15) =170576156a(16) =566725760a(17) =11804363619a(18) =43573050368

External references