%I #21 Jan 29 2019 10:36:11
%S 1,1,2,6,24,120,720,5040,30960,172200,899064,4553166,22934774,
%T 116914351,610093513,3222826972,17101449940,90706002192,479654768640,
%U 2527274267136,13280313508416,69734129749632,366283822765632,1925290900630896,10126754515065868
%N Number of permutations of length n within distance 6.
%C a(n) equals the permanent of the n X n matrix with 1's along the central thirteen diagonals, and 0's everywhere else. - _John M. Campbell_, Jul 10 2011
%H Alois P. Heinz, <a href="/A154655/b154655.txt">Table of n, a(n) for n = 0..1000</a> (terms n=1..400 from R. H. Hardin)
%H Torleiv Kløve, <a href="http://www.ii.uib.no/publikasjoner/texrap/pdf/2008-376.pdf">Spheres of Permutations under the Infinity Norm - Permutations with limited displacement</a>, Reports in Informatics, Department of Informatics, University of Bergen, Norway, no. 376, November 2008.
%F G.f. is a rational function f(x)/g(x) where f has degree 482 and g has degree 494.
%Y Cf. A000045, A002524, A002526, A072856, A154654.
%Y Column k=6 of A306209.
%K nonn,easy
%O 0,3
%A _Torleiv Kløve_, Jan 13 2009
%E a(0)=1 prepended by _Alois P. Heinz_, Jan 28 2019