Number of self-inverse permutations p on [n] with displacement of elements restricted by 6: |p(i)-i| <= 6.

A239078

Number of self-inverse permutations p on [n] with displacement of elements restricted by 6: |p(i)-i| <= 6.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =10a(5) =26a(6) =76a(7) =232a(8) =688a(9) =1950a(10) =5434a(11) =14910a(12) =40840a(13) =112063a(14) =309829a(15) =859684a(16) =2389776a(17) =6643900a(18) =18460796a(19) =51248304a(20) =142167544a(21) =394279264a(22) =1093484420a(23) =3033005340a(24) =8413870972a(25) =23343324312a(26) =64766314089a(27) =179693948237a(28) =498548997886

External references