Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and the total absolute value of displacements not greater than 2*(n-1).

A263899

Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and the total absolute value of displacements not greater than 2*(n-1).

Terms

    a(0) =1a(1) =2a(2) =6a(3) =13a(4) =31a(5) =73a(6) =172a(7) =399a(8) =932a(9) =2177a(10) =5081a(11) =11853a(12) =27662a(13) =64554a(14) =150639a(15) =351520a(16) =820296a(17) =1914208a(18) =4466904a(19) =10423760a(20) =24324417a(21) =56762346a(22) =132458006a(23) =309097941a(24) =721296815a(25) =1683185225a(26) =3927803988a(27) =9165743599a(28) =21388759708a(29) =49911830577

External references