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A071771 Least k > 0 such that the nextprime(k*primorial(n)) - k*primorial(n) is composite. 0
59, 413, 2018, 48907, 100284, 869700, 23094906 (list; graph; refs; listen; history; text; internal format)
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

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Last modified December 16 06:10 EST 2018. Contains 318158 sequences. (Running on oeis4.)