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 A284713 #27 Apr 11 2018 13:23:18 %S A284713 1,1,3,12,56,289,1604,9415,57801,368269,2421115,16352401,113075441, %T A284713 798316997,5741446395,41984708298,311673028845,2345644392051, %U A284713 17876342623580,137820598360123,1073961913716521,8452182814380104,67136452766364121,537890721293399309 %N A284713 Number of indecomposable permutations avoiding the pattern 4231. %H A284713 Vaclav Kotesovec, <a href="/A284713/b284713.txt">Table of n, a(n) for n = 1..50</a> %H A284713 A. L. L. Gao, S. Kitaev, P. B. Zhang. <a href="https://arxiv.org/abs/1605.05490">On pattern avoiding indecomposable permutations</a>, arXiv:1605.05490 [math.CO], 2016. %F A284713 G.f.: 1 - 1/g(x), where g(x) is the (at present unknown) g.f. for A061552. - _Vaclav Kotesovec_, Apr 03 2017 %Y A284713 Cf. A061552. %K A284713 nonn %O A284713 1,3 %A A284713 _N. J. A. Sloane_, Apr 02 2017 %E A284713 More terms from _Vaclav Kotesovec_, Apr 03 2017 %E A284713 Name corrected by _Michael D. Weiner_, Apr 10 2018