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 A348838 #37 Nov 05 2021 02:25:58
%S A348838 6,10,20,42,92,204,454,1010,2242,4962,10946,24066,52736,115186,250800,
%T A348838 544432,1178432,2543712,5476352,11760642,25196566,53861008,114889430,
%U A348838 244571174,519630462,1102021562,2333088968,4931232086,10406327848,21927562520,46138651012
%N A348838 Number of 3-sided prudent polygons of area n.
%H A348838 Nicholas R. Beaton and Anthony Guttmann, <a href="/A348838/b348838.txt">Table of n, a(n) for n = 1..3200</a>
%H A348838 Nicholas R. Beaton, Philippe Flajolet and Anthony J. Guttmann, <a href="http://arxiv.org/abs/1011.6195">The Enumeration of Prudent Polygons by Area and its Unusual Asymptotics</a>, arXiv:1011.6195 [math.CO], Nov 29, 2010.
%H A348838 Nicholas R. Beaton, Philippe Flajolet and Anthony J. Guttmann, <a href="https://doi.org/10.1016/j.jcta.2011.05.004">The Enumeration of Prudent Polygons by Area and its Unusual Asymptotics</a>, J. Comb. Theory Series A vol.118, 2011, pp.2261-2290.
%H A348838 Nicholas R. Beaton, Philippe Flajolet, Tim Garoni and Anthony J. Guttmann, <a href="https://doi.org/10.3233/fi-2012-686">Some New Self-avoiding Walk and Polygon Models</a>, Fundamenta Informaticae, vol. 117, 2012, pp. 19-33.
%F A348838 Reference gives generating function and asymptotics.
%t A348838 nmax = 40; Rest[CoefficientList[Series[2*q*(3 - 10*q + 9*q^2 - q^3)/((1 - 2*q)^2*(1 - q)) - 2*q^3*(1 - q)^2/(1 - 2*q)^2 * Sum[(-1)^m * q^(2*m) / ((1 - 2*q)^m*(1 - q - q^(m + 1))) * Product[(1 - q - q^k + q^(k+1) - q^(k+2)) / (1 - q - q^(k+1)), {k, 1, m-1}], {m, 1, nmax}], {q, 0, nmax}], q]]
%Y A348838 Cf. A052548, A348925.
%K A348838 nonn
%O A348838 1,1
%A A348838 _Vaclav Kotesovec_, following a suggestion from _Anthony Guttmann_, Nov 02 2021