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 A060898 #29 Oct 25 2018 17:12:48 %S A060898 1,4,14,54,200,776,2940,11466,43980,172170,665544,2612764,10154144, %T A060898 39949000,155864280,614260062,2403739140,9486263092,37209147800, %U A060898 147012850512,577741491404,2284848892872,8993216244896,35595538140656,140288753584200,555662416386840 %N A060898 Number of walks of length n on square lattice, starting at origin, staying in first, second and third quadrants. %C A060898 Is there a formula analogous to the (conjectured) formula for A060900? %H A060898 Alois P. Heinz, <a href="/A060898/b060898.txt">Table of n, a(n) for n = 0..1000</a> %H A060898 M. Bousquet-Mélou, <a href="http://arxiv.org/abs/1511.02111">Plane lattice walks avoiding a quadrant</a>, arXiv:1511.02111 [math.CO], 2015. %H A060898 Mireille Bousquet-Mélou, <a href="https://doi.org/10.1016/j.jcta.2016.06.010">Square lattice walks avoiding a quadrant</a>, Journal of Combinatorial Theory, Series A, Elsevier, 2016, Special issue for the 50th anniversary of the journal, 144, pp. 37-79. Also <hal-01225710v3>. See App. A. %H A060898 Kilian Raschel, Amélie Trotignon, <a href="https://arxiv.org/abs/1807.08610">On walks avoiding a quadrant</a>, arXiv:1807.08610 [math.CO], 2018. %Y A060898 Cf. A005566, A001700, A060897, A060899, A060900. %K A060898 nonn,easy,walk %O A060898 0,2 %A A060898 _David W. Wilson_, May 05 2001