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A261639 Values of n such that prime(n+1)!/prime(n) + 1 is a prime number. 0
2, 3, 4, 5, 19, 110 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(1) = 2, a(2) = 3, a(3) = 4, a(4) = 5. It can be seen as a nice consecutiveness on sequence for first four items. Another point is that sequence of prime(n+1)! / prime(n) is observed in A260754.

a(7) > 2300. - Giovanni Resta, Aug 28 2015

LINKS

Table of n, a(n) for n=1..6.

EXAMPLE

For n=2 the (prime(n+1)! / prime(n)) + 1 = 41. 41 is prime.

PROG

(PARI) for(n=1, 1e3, if(isprime(k=((prime(n+1)!/prime(n))+1)), print1(n", ")))

CROSSREFS

Cf. A260754.

Sequence in context: A145520 A061412 A165646 * A024635 A217679 A248901

Adjacent sequences:  A261636 A261637 A261638 * A261640 A261641 A261642

KEYWORD

nonn,more

AUTHOR

Altug Alkan, Aug 27 2015

STATUS

approved

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Last modified May 28 12:26 EDT 2017. Contains 287241 sequences.