A377401 a(n) = denominator((1/n!)*Sum_{k=1..n} 1/(2*k)).
1, 2, 8, 72, 576, 14400, 28800, 470400, 22579200, 1828915200, 18289152000, 2212987392000, 26555848704000, 4487938430976000, 62831138033664000, 942467070504960000, 30158946256158720000, 8715935468029870080000, 52295612808179220480000, 18878716223752698593280000
Offset: 0
Programs
-
Mathematica
a[n_]:=Denominator[Sum[1/(2*k),{k,n}]/n!]; Array[a,20,0] -
PARI
a(n) = denominator(sum(k=1, n, 1/(2*k))/n!); \\ Michel Marcus, Oct 29 2024
Formula
Conjecture: numerator((1/n!)*Sum_{k=1..n} 1/(2*k)) = A060746(n).