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A136352 Primorials P for which neither P-1 nor P+1 is prime. 5
510510, 9699690, 223092870, 6469693230, 7420738134810, 13082761331670030, 614889782588491410, 32589158477190044730, 1922760350154212639070, 117288381359406970983270, 7858321551080267055879090 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence is different from A121069 and A002110.

For almost all primes p, p# is in this sequence by Brun's theorem. - Charles R Greathouse IV, Sep 14 2015

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..350

FORMULA

Compute P = product of the first k primes. If P is neither preceded nor followed by a prime add P to the sequence.

EXAMPLE

13# = 30030 is preceded by a prime but is not followed by a prime. 17# = 510510 is neither preceded nor followed by a prime.

CROSSREFS

Cf. A136349, A136350, A136351, A002110, A121069.

Sequence in context: A258362 A147574 A046325 * A138207 A249881 A205291

Adjacent sequences:  A136349 A136350 A136351 * A136353 A136354 A136355

KEYWORD

easy,nonn

AUTHOR

Enoch Haga, Dec 25 2007

EXTENSIONS

Edited by and more terms from Charles R Greathouse IV, Sep 29 2008

STATUS

approved

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Last modified October 23 16:46 EDT 2019. Contains 328373 sequences. (Running on oeis4.)