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 A133262 #7 May 25 2015 03:58:31 %S A133262 1,4,8,172,5204,222716,12509188,889421564,78097622276,8312906703868, %T A133262 1056520142488580,158263730949406716,27626236450406776836, %U A133262 5563092167972597137404,1280742543230231763615748,334405228960123174787678204,98317121153947856929753989124,32339023133437156084762282819580,11831483864832785151824395066146820,4789379698138059405310741712024371196 %N A133262 Number of two-dimensional simple permutations. %C A133262 A two-dimensional permutation of n is a vector of three permutations, with the first element being the identity permutation. For example, ( (1 2 3) (1 3 2) (3 1 2) ) is a two-dimensional permutation of 3. The example is a simple two-dimensional permutation because none of the intervals of length 2 in the permutations is common among all three. On the other hand, ( (1 2 3) (1 3 2) (2 3 1) ) is not simple because the intervals covering 2 and 3 are common among all three permutations. %H A133262 M. H. Albert, M. D. Atkinson and M. Klazar, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL6/Albert/albert.html">The enumeration of simple permutations</a>, Journal of Integer Sequences 6 (2003), Article 03.4.4. %H A133262 Hao Zhang and Daniel Gildea, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL10/Zhang/dperm.html">Enumeration of Factorizable Multi-Dimensional Permutations</a>, J. Integer Sequences 10 (2007), Article 07.5.8. %Y A133262 Cf. A006318, A111111. %K A133262 nonn %O A133262 1,2 %A A133262 Hao Zhang and Daniel Gildea (zhanghao(AT)cs.rochester.edu), Oct 15 2007 %E A133262 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Feb 10 2008