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A066576 Composite Euclid numbers: numbers of the form p# + 1, where p# denotes the primorial of the prime p. 2
30031, 510511, 9699691, 223092871, 6469693231, 7420738134811, 304250263527211, 13082761331670031, 614889782588491411, 32589158477190044731, 1922760350154212639071, 117288381359406970983271 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

30031 appears in Wells's "Curious and Interesting Numbers" as the smallest composite number of the form p# + 1.

REFERENCES

David Wells, "The Penguin Dictionary of Curious and Interesting Numbers," Revised Edition, Penguin Books, London, England, 1997, page 166.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..341

MATHEMATICA

Do[c = Product[ Prime[i], {i, 1, n}] + 1; If[ !PrimeQ[c], Print[c]], {n, 1, 20} ]

PROG

(MAGMA) [a: n in [2..19]| not IsPrime(a) where a is 1+&*[NthPrime(k):k in [1..n]]]; // Marius A. Burtea, Feb 18 2020

CROSSREFS

Cf. A014545, A006862.

Sequence in context: A046324 A138206 A031853 * A104877 A237031 A027665

Adjacent sequences:  A066573 A066574 A066575 * A066577 A066578 A066579

KEYWORD

nonn

AUTHOR

Joseph L. Pe, Jan 07 2002

EXTENSIONS

Edited by Robert G. Wilson v, Jan 09 2002

STATUS

approved

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Last modified September 20 11:01 EDT 2020. Contains 337264 sequences. (Running on oeis4.)