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A119912 Scan A076368, discard any nonprimes. 1
2, 3, 3, 5, 3, 5, 3, 5, 7, 3, 7, 5, 3, 5, 7, 7, 3, 7, 5, 3, 7, 5, 7, 5, 3, 5, 3, 5, 5, 7, 3, 11, 3, 7, 7, 5, 7, 7, 3, 11, 3, 5, 3, 13, 13, 5, 3, 5, 7, 3, 11, 7, 7, 7, 3, 7, 5, 3, 11, 5, 3, 5, 7, 11, 3, 5, 7, 7, 7, 5, 7, 5, 11, 3, 11, 3, 7, 5, 7, 5, 3, 5, 13, 5, 5, 7, 13, 3, 19, 7, 11, 7, 7, 3, 7, 11, 7, 7, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Primes that are one greater than the difference between consecutive primes.

LINKS

Table of n, a(n) for n=0..98.

Cino Hilliard, Frequency of primes.

EXAMPLE

The first 4 consecutive prime pairs are (2,3),(3,5),(5,7),(7,11). The differences + 1 are the primes 2,3,3,5, the first four entries in the sequence.

MAPLE

P:=proc(n) local cont, i, j, k, w; for i from 1 by 1 to n do k:=ithprime(i); w:=ithprime(i+1); if isprime(w-k+1) then print(w-k+1); fi; od; end: P(10000);

MATHEMATICA

Select[Differences[Prime[Range[200]]]+1, PrimeQ] (* Harvey P. Dale, Jul 02 2017 *)

PROG

(PARI) diffp1p2(n) = { local(p1, p2, y); for(x=1, n, p1=prime(x); p2=prime(x+1); y=(p2-p1)+1; if(isprime(y), print1(y", ") ) ) } - Cino Hilliard, May 23 2007

CROSSREFS

Cf. A076368.

Sequence in context: A229703 A131320 A020483 * A076368 A279931 A071049

Adjacent sequences:  A119909 A119910 A119911 * A119913 A119914 A119915

KEYWORD

easy,nonn

AUTHOR

Paolo P. Lava and Giorgio Balzarotti, Aug 02 2006

EXTENSIONS

Edited by N. J. A. Sloane, Jul 02 2008 at the suggestion of R. J. Mathar

STATUS

approved

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Last modified June 15 04:47 EDT 2021. Contains 345043 sequences. (Running on oeis4.)