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A066726 Numbers n such that binomial(2n, n) - 1 is prime. 16
2, 3, 5, 9, 15, 29, 43, 51, 113, 184, 213, 222, 267, 279, 369, 402, 441, 603, 812, 839, 902, 1422, 1542, 1824, 2983, 3065, 3911, 3958, 4192, 4587, 4865, 5543, 5837, 7902, 9299, 9722, 10412, 10648, 11498, 12803, 14428, 15876 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

I.e., numbers n such that (2*n)!/(n!)^2-1 is prime. - Hugo Pfoertner, Sep 25 2005

LINKS

Table of n, a(n) for n=1..42.

MATHEMATICA

Do[ If[ PrimeQ[ Binomial[2n, n] - 1], Print[n]], {n, 1, 2000} ]

PROG

(PARI) is(n)=isprime(binomial(2*n, n)-1) \\ Charles R Greathouse IV, Feb 17 2017

CROSSREFS

Cf. A066699, A085793.

Cf. A092751 = primes of the form (2*n)!/(n!)^2-1, A112853 = (2*n)!/n!-1 is prime, A112855 = (2*n)!/n!+1 is prime, A112859 = (2*n)!/(n!)^2+1 is prime, A112861 = (2*n)!/(2*(n!)^2)-1 is prime, A112863 = (2*n)!/(2*(n!)^2)+1 is prime. - Hugo Pfoertner, Sep 25 2005

Sequence in context: A092424 A167510 A191701 * A124642 A269153 A232866

Adjacent sequences:  A066723 A066724 A066725 * A066727 A066728 A066729

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Jan 15 2002

EXTENSIONS

More terms from Ed Pegg Jr, Sep 10 2003

Edited by N. J. A. Sloane, Aug 23 2008 at the suggestion of R. J. Mathar

STATUS

approved

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Last modified July 17 18:47 EDT 2019. Contains 325109 sequences. (Running on oeis4.)