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A118332 Primes of the form n!! + (n+1)!!. 1
2, 3, 5, 11, 23 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

These are all primes of the form n!! + (n+1)!! Corresponding values of n are 0, 1, 2, 3, 4. At n>4, n!! + (n+1)!! is always composite, cf. A118333.

Apparently also the set of primes p(n) such that p(n)^2 - 2^n is prime. - Irina Gerasimova, May 09 2013

LINKS

Table of n, a(n) for n=1..5.

CROSSREFS

Cf. A118333.

Sequence in context: A117221 A073879 A073880 * A118333 A131101 A188534

Adjacent sequences:  A118329 A118330 A118331 * A118333 A118334 A118335

KEYWORD

fini,full,nonn

AUTHOR

Zak Seidov, Apr 23 2006

STATUS

approved

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Last modified April 19 10:30 EDT 2021. Contains 343112 sequences. (Running on oeis4.)