Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and exactly two more elements moved upwards than downwards.

A263781

Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and exactly two more elements moved upwards than downwards.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =3a(7) =11a(8) =31a(9) =93a(10) =248a(11) =670a(12) =1724a(13) =4434a(14) =11120a(15) =27772a(16) =68402a(17) =167695a(18) =407659a(19) =986955a(20) =2376323a(21) =5702352a(22) =13631753a(23) =32500113a(24) =77272919a(25) =183336571a(26) =434092838a(27) =1026096990a(28) =2421667040a(29) =5707720617

External references