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 A293318 #17 May 14 2025 10:56:36
%S A293318 1,4,86,3480,208054,16486680,1628301884,192666441968,26569595376038,
%T A293318 4184718381424152,741138328282003860,145795774074768177360,
%U A293318 31540994233548116475196,7442380580681963411363440,1902155375416975061879918520,523496081998297020687019596000
%N A293318 a(n) = (2*n)! * [x^(2*n)] (-log(sqrt(1 - 2*x)))^n/(sqrt(1 - 2*x)*n!).
%H A293318 Seiichi Manyama, <a href="/A293318/b293318.txt">Table of n, a(n) for n = 0..300</a>
%F A293318 a(n) ~ c * d^n * (n-1)!, where d = -16*LambertW(-1, -exp(-1/2)/2)^2 / (1 + 2*LambertW(-1, -exp(-1/2)/2)) = 19.643259858273023595... (see also A265846) and c = 1/(2*Pi*sqrt(1 + 1/LambertW(-1, -exp(-1/2)/2))) = 0.2425219128152359859... - _Vaclav Kotesovec_, Oct 18 2017, updated Mar 17 2024 and May 14 2025
%t A293318 Table[(2 n)! SeriesCoefficient[(-Log[Sqrt[1 - 2 x]])^n/(Sqrt[1 - 2 x] n!), {x, 0, 2 n}], {n, 0, 15}]
%Y A293318 Central terms of triangles A028338, A039757 (gives absolute values) and A109692.
%Y A293318 Cf. A265846.
%K A293318 nonn
%O A293318 0,2
%A A293318 _Ilya Gutkovskiy_, Oct 06 2017