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.
0, 0, 0, 0, 35, 210, 1596, 12992, 118863, 1202870, 13361392, 161638752, 2115684259, 29792671818, 449145795900, 7217975402752, 123180993414207, 2224874726830638, 42402252681323840, 850380681002034880, 17902407539998807875, 394741856473979171586, 9097740802923890621468
Offset: 1
Keywords
Crossrefs
Cf. A167760.