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 A239081 #5 Mar 10 2014 13:15:16 %S A239081 1,1,2,4,10,26,76,232,764,2620,9496,33076,112428,372436,1214976, %T A239081 3913582,12529522,39989374,127728664,409169795,1317486613,4256424244, %U A239081 13780938480,44667060684,144831314468,469535390016,1521506451968,4927356770176,15947637013296 %N A239081 Number of self-inverse permutations p on [n] with displacement of elements restricted by 9: |p(i)-i| <= 9. %H A239081 Joerg Arndt and Alois P. Heinz, <a href="/A239081/b239081.txt">Table of n, a(n) for n = 0..1000</a> %Y A239081 Column k=9 of A238888. %Y A239081 Cf. A000085. %K A239081 nonn %O A239081 0,3 %A A239081 _Joerg Arndt_ and _Alois P. Heinz_, Mar 10 2014