

A071771


Least k > 0 such that the nextprime(k*primorial(n))  k*primorial(n) is composite.


0




OFFSET

1,1


LINKS

Table of n, a(n) for n=1..7.


EXAMPLE

For a(2): the second primorial (A002110) is 6. It is not until k = 413, or 6*413 = 2478, that the next prime > 2478 = 2503 less 2478 which equals 25 is a composite.


MATHEMATICA

Do[p = Product[ Prime[i], {i, 1, n}]; k = 1; While[ q = NextPrim[k*p]  k*p; q == 1  PrimeQ[q], k++ ]; Print[k], {n, 1, 6}]


CROSSREFS

Cf. A002110, A005235, A071572.
Sequence in context: A118624 A244772 A142604 * A235223 A235216 A284754
Adjacent sequences: A071768 A071769 A071770 * A071772 A071773 A071774


KEYWORD

nonn


AUTHOR

David W. Wilson and Robert G. Wilson v, Jun 04 2002


STATUS

approved



