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A243158 Smallest k>=0 such that prime(n)*prime(n+k) + 2 is prime. 3
0, 1, 1, 3, 1, 5, 1, 3, 4, 4, 3, 5, 2, 6, 13, 5, 6, 1, 9, 28, 8, 2, 10, 8, 5, 8, 3, 3, 31, 2, 2, 9, 6, 1, 3, 6, 2, 5, 4, 1, 10, 3, 7, 3, 6, 7, 4, 4, 1, 14, 1, 1, 4, 4, 18, 1, 8, 1, 3, 10, 3, 1, 6, 1, 7, 2, 26, 19, 6, 2, 8, 30, 23, 6, 19, 5, 1, 1, 12, 1, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,4

COMMENTS

A dual sequence to A243154. The sequence contains a unique zero term. Indeed, every prime p>3 has the form 3*k +/- 1. So, p^2 + 2 == 0 (mod 3).

LINKS

Table of n, a(n) for n=2..82.

PROG

(PARI) vector(200, n, k=0; while(!isprime(prime(n+1)*prime(n+1+k)+2), k++); k) \\ Colin Barker, May 31 2014

CROSSREFS

Cf. A243154.

Sequence in context: A016475 A037227 A056753 * A154723 A273262 A274532

Adjacent sequences:  A243155 A243156 A243157 * A243159 A243160 A243161

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, May 31 2014

EXTENSIONS

More terms from Colin Barker, May 31 2014

STATUS

approved

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Last modified November 14 12:21 EST 2019. Contains 329114 sequences. (Running on oeis4.)