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A023200 Primes p such that p + 4 is also prime. 76
3, 7, 13, 19, 37, 43, 67, 79, 97, 103, 109, 127, 163, 193, 223, 229, 277, 307, 313, 349, 379, 397, 439, 457, 463, 487, 499, 613, 643, 673, 739, 757, 769, 823, 853, 859, 877, 883, 907, 937, 967, 1009, 1087, 1093, 1213, 1279, 1297, 1303, 1423, 1429, 1447, 1483 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Smaller member p of cousin prime pairs (p, p+4).

A015913 contains the composite number 305635357, so is different from the present sequence and A029710 (305635357 is the only composite member of A015913 < 10^9) - Jud McCranie (JudMcCranie(AT)ugaalum.uga.edu), Jan 07, 2001.

LINKS

T. D. Noe, Table of n, a(n) for n=1..10000

A. Granville and G. Martin, Prime number races

Eric Weisstein's World of Mathematics, Cousin Primes

Eric Weisstein's World of Mathematics, Twin Primes

Index entries for primes, gaps between

FORMULA

a(n) = A046132(n) - 4 = A087679(n) - 2.

MAPLE

A023200 := proc(n) option remember; if n = 1 then 3; else p := nextprime(procname(n-1)) ; while not isprime(p+4) do p := nextprime(p) ;  end do: p ; end if; end proc: # R. J. Mathar, Sep 03 2011

MATHEMATICA

Select[Range[10^2], PrimeQ[ # ]&&PrimeQ[ #+4] &] (from Vladimir Orlovsky (4vladimir(AT)gmail.com), Apr 29 2008)

CROSSREFS

Essentially the same as A029710.

Cf. A000010, A003557, A007947, A046132, A098429.

Sequence in context: A048977 A154650 A015913 * A046136 A098044 A134765

Adjacent sequences:  A023197 A023198 A023199 * A023201 A023202 A023203

KEYWORD

nonn

AUTHOR

David W. Wilson (davidwwilson(AT)comcast.net)

EXTENSIONS

Definition revised by N. J. A. Sloane, Mar 05 2010

Definition modified by Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 02 2009

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Last modified February 14 08:20 EST 2012. Contains 205610 sequences.