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A140382 Prime pairs of the form (p,p+4). 3
3, 7, 7, 11, 13, 17, 19, 23, 37, 41, 43, 47, 67, 71, 79, 83, 97, 101, 103, 107, 109, 113, 127, 131, 163, 167, 193, 197, 223, 227, 229, 233, 277, 281, 307, 311, 313, 317, 349, 353, 379, 383, 397, 401, 439, 443, 457, 461, 463, 467, 487, 491, 499, 503, 613, 617 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

The two primes p and p+4 are not necessarily adjacent.

Removal of duplicates yields A094343. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 27 2008]

FORMULA

a(2n-1)=A023200(n). a(2n)=A046132(n).

EXAMPLE

The pairs are (3,7), (7,11), (13,17) etc.

MATHEMATICA

Flatten[{#, #+4}&/@Select[Prime[Range[200]], PrimeQ[#+4]&]]  (* From Harvey P. Dale, Apr 13 2011 *)

CROSSREFS

Cf. A000040.

Sequence in context: A020764 A010625 A011322 * A179873 A080457 A119644

Adjacent sequences:  A140379 A140380 A140381 * A140383 A140384 A140385

KEYWORD

nonn,less

AUTHOR

Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jun 14 2008

EXTENSIONS

Edited by R. J. Mathar, Jun 16 2008

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Last modified February 15 21:56 EST 2012. Contains 205860 sequences.