Number of permutations p of [n] with no fixed points and cyclic displacement of elements restricted by three: p(i)<>i and (i-p(i) mod n <= 3 or p(i)-i mod n <= 3).
A260081
Number of permutations p of [n] with no fixed points and cyclic displacement of elements restricted by three: p(i)<>i and (i-p(i) mod n <= 3 or p(i)-i mod n <= 3).
Terms
- a(0) =1a(1) =0a(2) =1a(3) =2a(4) =9a(5) =44a(6) =265a(7) =1854a(8) =4752a(9) =12072a(10) =30500a(11) =76038a(12) =190656a(13) =481318a(14) =1224852a(15) =3117528a(16) =7944464a(17) =20283046a(18) =51912320a(19) =133129054a(20) =341972624a(21) =879678624a(22) =2266157892a(23) =5846150862a(24) =15101728320a(25) =39058470566a(26) =101135401556a(27) =262158219552a(28) =680253580304
External references
- oeis: A260081