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 A373752 #10 Jun 17 2024 07:56:26
%S A373752 1,1,1,1,2,8,33,136,670,3968,25593,176896,1344154,11184128,99897361,
%T A373752 951878656,9687175862,104932671488,1202872541673,14544442556416,
%U A373752 185158504589938,2475749026562048,34676498435503489,507711943253426176,7757079744889072462,123460740095103991808
%N A373752 a(n) = Sum_{k=0..n-2} A205497(n, k) * (1 - k mod 2) if n >= 2, a(0) = a(1) = 1.
%C A373752 Number of linear extensions in L(eps Z_n) that have an even number of descents. (See Petersen and Yan Zhuang, p. 6.)
%H A373752 T. Kyle Petersen and Yan Zhuang, <a href="https://arxiv.org/abs/2403.07181">Zig-zag Eulerian polynomials</a>, arXiv:2403.07181 [math.CO], 2024.
%F A373752 a + A373753 = A000111.
%p A373752 enum := L -> ListTools:-Enumerate(L):
%p A373752 seq(add(c[2]*irem(c[1], 2), c = enum([A205497row(n)])), n = 0..25);
%Y A373752 Cf. A205497, A000111, A373753.
%K A373752 nonn
%O A373752 0,5
%A A373752 _Peter Luschny_, Jun 16 2024