This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A154657 #23 Jan 29 2019 10:36:27 %S A154657 1,1,2,6,24,120,720,5040,40320,362880,2943360,21898800,152622000, %T A154657 1017952680,6623303544,42700751022,276054834902,1805409270031, %U A154657 12020754177001,80930279045116,548117873866228,3720269813727312,25239622338694272,170893063638209664 %N A154657 Number of permutations of length n within distance 8. %C A154657 a(n) equals the permanent of the n X n matrix with 1's along the central seventeen diagonals, and 0's everywhere else. - _John M. Campbell_, Jul 10 2011 %H A154657 Alois P. Heinz, <a href="/A154657/b154657.txt">Table of n, a(n) for n = 0..800</a> (terms n=1..177 from R. H. Hardin) %H A154657 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. %Y A154657 Cf. A000045, A002524, A002526, A072856, A154654-A154656. %Y A154657 Column k=8 of A306209. %K A154657 nonn %O A154657 0,3 %A A154657 _Torleiv Kløve_, Jan 13 2009 %E A154657 a(0)=1 prepended by _Alois P. Heinz_, Jan 28 2019