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

A321050

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

Terms

    a(0) =0a(1) =20a(2) =111a(3) =396a(4) =1285a(5) =4312a(6) =15437a(7) =55572a(8) =196288a(9) =678270a(10) =2311191a(11) =7856610a(12) =26732463a(13) =90996552a(14) =309390463a(15) =1049670138a(16) =3554983881a(17) =12027825752a(18) =40676758809a(19) =137534141216a(20) =464908099716

External references