Number of permutations of [n] having no adjacent 4-cycles, i.e., no cycles of the form (i, i+1, i+2, i+3).
A177253
Number of permutations of [n] having no adjacent 4-cycles, i.e., no cycles of the form (i, i+1, i+2, i+3).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =23a(5) =118a(6) =714a(7) =5016a(8) =40201a(9) =362163a(10) =3623772a(11) =39876540a(12) =478639079a(13) =6223394516a(14) =87138394540
External references
- oeis: A177253