

A059322


First differences of sequence of consecutive safe primes.


2



2, 4, 12, 24, 12, 24, 24, 60, 12, 48, 36, 84, 12, 24, 84, 12, 24, 60, 24, 132, 120, 24, 24, 96, 36, 168, 96, 24, 12, 48, 72, 48, 36, 96, 204, 84, 120, 12, 24, 36, 108, 240, 12, 120, 240, 60, 24, 60, 36, 24, 96, 48, 36, 264, 156, 156, 24, 60, 84, 60, 72, 48, 12, 120, 24
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OFFSET

0,1


LINKS

G. C. Greubel, Table of n, a(n) for n = 0..5000


FORMULA

a(n) = A005385(n+1)  A005385(n).  corrected by Harvey P. Dale, Jan 12 2011 and Zak Seidov, Sep 19 2016


EXAMPLE

Except for (5,7) and (7,11), all terms are divisible by 12, since safe primes are congruent to 5 modulo 6 except 7 and safe_prime+6 is not a safe prime. Closest safe primes differ by 12 like (11,23) or (83207,83219).


MATHEMATICA

Differences[Select[Prime[Range[500]], PrimeQ[(#1)/2]&]] (* Harvey P. Dale, Jan 12 2011 *)


CROSSREFS

Cf. A005385, A033299.
Sequence in context: A291404 A295954 A052416 * A163908 A230481 A212169
Adjacent sequences: A059319 A059320 A059321 * A059323 A059324 A059325


KEYWORD

nonn


AUTHOR

Labos Elemer, Jan 26 2001


STATUS

approved



