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 A284718 #19 Dec 20 2017 03:36:22 %S A284718 1,1,1,3,13,69,396,2355,14363,89706,573828,3758866,25195016,172591294, %T A284718 1206482317,8592827996,62257890162,458214977642,3421294482237, %U A284718 25884913987768,198236423171483,1535315006313002,12015208271571543,94943908405295171,757044806198966152 %N A284718 Number of indecomposable permutations avoiding the pattern 1324. %H A284718 Bjarki Ágúst Guðmundsson, <a href="/A284718/b284718.txt">Table of n, a(n) for n = 0..50</a> (terms 25..50 by Bjarki Ágúst Guðmundsson, computed using Kotesovec's formula and terms from the Conway/Guttmann/Zinn-Justin reference) %H A284718 Andrew R. Conway, Anthony J. Guttmann and Paul Zinn-Justin, <a href="https://arxiv.org/abs/1709.01248">1324-avoiding permutations revisited</a>, arXiv preprint arXiv:1709.01248 [math.CO], 2017. %H A284718 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 A284718 For n>1, a(n) = A061552(n) + 3*A000108(n) - A000108(n+1) - 2*A000108(n-1). - _Vaclav Kotesovec_, Apr 02 2017 %Y A284718 Cf. A061552. %K A284718 nonn %O A284718 0,4 %A A284718 _N. J. A. Sloane_, Apr 02 2017 %E A284718 More terms from _Vaclav Kotesovec_, Apr 02 2017 %E A284718 a(0) prepended by _Bjarki Ágúst Guðmundsson_, Dec 18 2017