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A066699 Numbers n such that binomial(2n,n)+1 is prime. 15
1, 2, 4, 7, 12, 19, 22, 38, 46, 62, 68, 72, 84, 166, 184, 214, 340, 348, 445, 517, 692, 817, 1316, 1381, 2554, 2713, 5261, 6209, 6735, 7920, 8207, 8772, 9530, 13075, 13302, 13405, 15002, 16371, 19346, 24151, 26555, 28188, 29235, 33536 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(45) > 40000. All the primes corresponding to terms up to a(44) have been certified by the PFGW software performing the Brillhart-Lehmer-Selfridge N-1 test. - Giovanni Resta, Apr 05 2017
REFERENCES
Aigner and Ziegler. Proofs from the Book, 2nd edition. Springer-Verlag, 2001.
LINKS
EXAMPLE
C(4,2) + 1 = 7, a prime; so 2 is a term of the sequence.
MATHEMATICA
Do[If[PrimeQ[Binomial[2 a, a]+1], a >>>"C:\prime.txt"], {a, 1, 20000}] (* Ed Pegg Jr *)
Select[Range[1, 5 * 10^2], PrimeQ[Binomial[2* #, # ] + 1] &]
PROG
(PARI) is(n)=isprime(binomial(2n, n)+1) \\ Charles R Greathouse IV, May 15 2013
CROSSREFS
Sequence in context: A105807 A209616 A192521 * A188425 A087149 A090853
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Jan 14 2002
EXTENSIONS
More terms (not certified primes) from Jason Earls and Robert G. Wilson v, Jan 15 2002
More terms from Ed Pegg Jr, Sep 10 2003
a(40)-a(44) from Giovanni Resta, Apr 05 2017
STATUS
approved

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Last modified March 28 11:59 EDT 2024. Contains 371254 sequences. (Running on oeis4.)