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A118223 Numbers n such that n! * p(n)# - 1 is prime. 1
2, 3, 4, 9, 11, 12, 13, 50, 73, 81, 82, 115, 308, 405 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Fourteen terms found and primes proved by PrimeForm ([N+1, Brillhart-Lehmer-Selfridge]). There are no more terms <= 2100.

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

3 is a term as 3! * p(3)# - 1 = 3*2*1 * 5*3*2 - 1 = 179, a prime.

CROSSREFS

Cf. A118222.

Sequence in context: A068334 A283874 A263092 * A212989 A211546 A093514

Adjacent sequences:  A118220 A118221 A118222 * A118224 A118225 A118226

KEYWORD

nonn

AUTHOR

Rick L. Shepherd, Apr 16 2006

STATUS

approved

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Last modified September 27 04:10 EDT 2021. Contains 347673 sequences. (Running on oeis4.)