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 A225963 #10 Aug 05 2015 16:51:37 %S A225963 1,5,25,134,815,5657,44549,394266,3883182,42174500,500942458, %T A225963 6460077110,89875729761,1341559805867,21382747361727,362402701510514, %U A225963 6507348542427217,123394642353693319,2463866954996239829,51670868533003154264,1135456889195715187948 %N A225963 Number of permutations of [n] having exactly 2 strong fixed blocks. %C A225963 See A186373 for the definition of strong fixed blocks. %H A225963 Alois P. Heinz, <a href="/A225963/b225963.txt">Table of n, a(n) for n = 4..450</a> %F A225963 a(n) ~ n! / n^2. - _Vaclav Kotesovec_, Aug 29 2014 %Y A225963 Column k=2 of A186373. %K A225963 nonn %O A225963 4,2 %A A225963 _Alois P. Heinz_, May 22 2013