OFFSET
1,2
EXAMPLE
a(4) = 4! * A002805(4) = 24 * 12 = 288.
MAPLE
H:= proc(n) H(n):= 1/n +`if`(n=1, 0, H(n-1)) end:
a:= n-> denom(H(n))*n!:
seq(a(n), n=1..20); # Alois P. Heinz, Jul 21 2018
MATHEMATICA
a[n_] := n! Denominator@HarmonicNumber@n; Array[a, 18] (* Robert G. Wilson v, Jun 30 2018 *)
PROG
(PARI) a(n) = n! * denominator(sum(k=1, n, 1/k)); \\ Michel Marcus, Aug 12 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Matthew Campbell, Jun 29 2018
STATUS
approved