OFFSET
0,2
COMMENTS
Sum_{n>=0} 1/a(n) = 1.765582555581609270...
EXAMPLE
a(5) = 2*3*5*7*11 / 2*3 = 385.
PROG
(PARI) a(n) = prod(k=1, n, prime(k))/prod(k=1, n-1, if (isprime(k), k, 1)); \\ Michel Marcus, Mar 26 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Pedro Caceres, Mar 24 2018
STATUS
approved