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A231483 Smallest k > A082467(n) such that n-k and n+k are both prime. 1
9, 8, 15, 18, 7, 12, 15, 10, 15, 18, 7, 28, 15, 10, 27, 12, 7, 24, 15, 8, 21, 18, 5, 30, 15, 8, 27, 24, 11, 18, 9, 10, 15, 30, 13, 18, 15, 10, 21, 30, 7, 42, 21, 10, 33, 18, 7, 30, 21, 10, 9, 18, 11, 30, 27, 8, 33, 24, 11, 48, 21, 8, 21, 30 (list; graph; refs; listen; history; text; internal format)
OFFSET

20,1

COMMENTS

Starting at n=20 just because there are some n<20 without solution like for n=19, for the least k (A082467) it start at 4 as no solution for n<4.

LINKS

Pierre CAMI, Table of n, a(n) for n = 20..10000

PROG

(PARI) a(n) = {k=1; while(isprime(n-k)*isprime(n+k) == 0, k++); k++; while(isprime(n-k)*isprime(n+k) == 0, k++); k; } \\ Michel Marcus, Nov 10 2013

CROSSREFS

Cf. A082467.

Sequence in context: A272962 A137392 A307639 * A309656 A309657 A296615

Adjacent sequences:  A231480 A231481 A231482 * A231484 A231485 A231486

KEYWORD

nonn

AUTHOR

Pierre CAMI, Nov 09 2013

STATUS

approved

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Last modified June 18 00:21 EDT 2021. Contains 345088 sequences. (Running on oeis4.)