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 A377401 #9 Oct 29 2024 15:41:32
%S A377401 1,2,8,72,576,14400,28800,470400,22579200,1828915200,18289152000,
%T A377401 2212987392000,26555848704000,4487938430976000,62831138033664000,
%U A377401 942467070504960000,30158946256158720000,8715935468029870080000,52295612808179220480000,18878716223752698593280000
%N A377401 a(n) = denominator((1/n!)*Sum_{k=1..n} 1/(2*k)).
%F A377401 Conjecture: numerator((1/n!)*Sum_{k=1..n} 1/(2*k)) = A060746(n).
%t A377401 a[n_]:=Denominator[Sum[1/(2*k),{k,n}]/n!]; Array[a,20,0]
%o A377401 (PARI) a(n) = denominator(sum(k=1, n, 1/(2*k))/n!); \\ _Michel Marcus_, Oct 29 2024
%Y A377401 Cf. A000142, A005843, A060746, A377400.
%K A377401 nonn,frac
%O A377401 0,2
%A A377401 _Stefano Spezia_, Oct 27 2024