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 A373753 #9 Jun 17 2024 07:56:30
%S A373753 0,0,0,1,3,8,28,136,715,3968,24928,176896,1358611,11184128,99463620,
%T A373753 951878656,9704336283,104932671488,1202007133768,14544442556416,
%U A373753 185212683647587,2475749026562048,34672375957634412,507711943253426176,7757454418668014443,123460740095103991808
%N A373753 a(n) = Sum_{k=0..n-2} A205497(n, k) * (k mod 2).
%C A373753 Number of linear extensions in L(eps Z_n) that have an odd number of descents. (See Petersen and Yan Zhuang, p. 6.)
%H A373753 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 A373753 a + A373752 = A000111.
%p A373753 enum := L -> ListTools:-Enumerate(L):
%p A373753 seq(add(c[2]*(1-irem(c[1], 2)), c = enum([A205497row(n)])), n = 0..25);
%Y A373753 Cf. A205497, A000111, A373752.
%K A373753 nonn
%O A373753 0,5
%A A373753 _Peter Luschny_, Jun 16 2024