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A064278 Numbers n such that n! + prime(n) is prime. 3
1, 2, 3, 4, 5, 6, 9, 11, 17, 18, 25, 31, 40, 96, 174, 193, 204, 269, 523, 650, 659, 797, 1437, 1862, 2515, 4983 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

The numbers corresponding to 2515 and 4983 are probable primes. [From F. Firoozbakht (mymontain(AT)yahoo.com), Oct 15 2009]

EXAMPLE

n=5: 5! = 120 and prime(5) = 11, 120+11 = 131.

6 is listed because 6!+p(6)=720+13=733 is prime

MATHEMATICA

Do[ If[ PrimeQ[ n! + Prime[ n ] ], Print[ n ] ], {n, 1, 700} ]

PROG

(PARI) for(n=1, 100, if(isprime(n!+prime(n)), print(n)))

CROSSREFS

Cf. A063499 "Primes of form p(n) + n!, where p(n) is the n-th prime." [From Alexander R. Povolotsky (pevnev(AT)juno.com), Aug 13 2008]

Sequence in context: A036023 A119952 A102571 * A125155 A091179 A036027

Adjacent sequences:  A064275 A064276 A064277 * A064279 A064280 A064281

KEYWORD

nonn

AUTHOR

Jason Earls (zevi_35711(AT)yahoo.com), Sep 24 2001

EXTENSIONS

More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 28 2001

More terms from John Sillcox (JMS21187(AT)aol.com), Apr 05 2003

Two more terms from F. Firoozbakht (mymontain(AT)yahoo.com), Oct 15 2009

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Last modified February 17 16:00 EST 2012. Contains 206050 sequences.