a(n) is the number of permutations w of [n] with no w(i)+1 == w(i+1) (mod n) that are not simply cyclic permutations of the numbers 1 to n in backwards order.
A345655
a(n) is the number of permutations w of [n] with no w(i)+1 == w(i+1) (mod n) that are not simply cyclic permutations of the numbers 1 to n in backwards order.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =35a(5) =210a(6) =1596a(7) =12992a(8) =118863a(9) =1202870a(10) =13361392a(11) =161638752a(12) =2115684259a(13) =29792671818a(14) =449145795900
External references
- oeis: A345655