OFFSET
1,4
PROG
(PARI) a1(n)=prod(i=1, n, prime(i));
b1(n)=prod(i=1, n, prime(n+1)%prime(i));
a(n)=if(n<0, 0, denominator(a1(n)/b1(n)));
for(n=1, 25, print1(a(n) ", "))
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Creighton Dement, Sep 24 2009
STATUS
approved