Number of permutations of [n] with no fixed points where the maximal displacement of an element equals three.

A321049

Number of permutations of [n] with no fixed points where the maximal displacement of an element equals three.

Terms

    a(0) =0a(1) =5a(2) =18a(3) =44a(4) =116a(5) =331a(6) =932a(7) =2532a(8) =6720a(9) =17804a(10) =47280a(11) =125460a(12) =331736a(13) =874973a(14) =2305750a(15) =6075184a(16) =16001968a(17) =42130767a(18) =110885496a(19) =291792264a(20) =767776064a(21) =2020061968a(22) =5314529928a(23) =13981117152a(24) =36779372688a(25) =96751538581a(26) =254510051546a(27) =669494097852

External references