A variant of payphone permutations: given a circular booth with n payphones, one of which is already occupied, a(n) is the number ways for n-1 people to choose the payphones in order, where each person chooses an unoccupied payphone such that the closest occupied payphone is as distant as possible.

A362192

A variant of payphone permutations: given a circular booth with n payphones, one of which is already occupied, a(n) is the number ways for n-1 people to choose the payphones in order, where each person chooses an unoccupied payphone such that the closest occupied payphone is as distant as possible.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =2a(4) =12a(5) =24a(6) =48a(7) =48a(8) =960a(9) =5760a(10) =20160a(11) =80640a(12) =322560a(13) =645120a(14) =967680a(15) =1935360a(16) =139345920a(17) =2786918400a(18) =30656102400a(19) =367873228800

External references