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A114227 Smallest odd prime q that makes the n-th prime p[n] plus 2*q (p[n]+2q) a prime. +0
17
3, 3, 3, 3, 3, 5, 3, 7, 3, 3, 3, 5, 3, 3, 7, 3, 3, 13, 3, 5, 3, 7, 3, 3, 3, 3, 11, 7, 5, 3, 7, 5, 7, 3, 3, 5, 3, 3, 7, 5, 3, 3, 7, 17, 11, 3, 3, 5, 3, 19, 5, 3, 3, 3, 7, 3, 3, 13, 5, 7, 3, 3, 17, 7, 3, 5, 3, 5, 3, 7, 3, 3, 5, 3, 37, 11, 19, 5, 7, 5, 13, 3, 5, 3, 7, 3, 3, 23, 37, 31, 11, 43, 5, 3, 7, 13, 17 (list; graph; listen)
OFFSET

3,1

EXAMPLE

p[3]=5, 5+2*3=11 is prime, so q[3]=3;

p[4]=7, 7+2*3=13 is prime, so q[4]=3;

...

p[20]=71, 71+2*13=97 is prime, so q[20]=13

MATHEMATICA

Table[p1 = Prime[n1]; n2 = 2; p2 = 3; While[ cp = p1 + 2*p2; ! PrimeQ[cp], n2++; p2 = Prime[n2]]; p2, {n1, 3, 202}]

CROSSREFS

Sequence in context: A105159 A050499 A147752 this_sequence A112593 A113215 A105591

Adjacent sequences: A114224 A114225 A114226 this_sequence A114228 A114229 A114230

KEYWORD

easy,nonn

AUTHOR

Lei Zhou (lzhou5(AT)emory.edu), Nov 18 2005

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Last modified November 24 23:16 EST 2009. Contains 167481 sequences.


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