OFFSET
0,5
COMMENTS
EXAMPLE
a(0) = 1/1, a(1)= 2/2, a(2) = 6/6, a(3) = 30/30, a(4) =210/42=5.
By product (see A080092):
1,
1,
1,
1,
5,
7 * 11,
5 * 7 *13,
11 * 17,
5 * 7 *11 *13 *17 *19,
7 * 11 *13 *19 *23,
5 * 11 *13 *17 *23 *29,
7 * 13 *17 *19 *23 *29 *31,
5 * 7 *11 *13 *17 *19 *29 *31 *37.
MATHEMATICA
a[n_] := Product[ Prime[k], {k, 1, n}] / Denominator[ BernoulliB[2*n-2] ]; a[0] = a[1] = 1; Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Mar 15 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul Curtz, Mar 10 2013
EXTENSIONS
More terms from Jean-François Alcover, Mar 15 2013
STATUS
approved