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A100742 Smallest prime p such that (p+prime(n))/2 is prime. 1
2, 3, 5, 3, 3, 13, 5, 3, 3, 5, 3, 37, 5, 3, 11, 5, 3, 13, 7, 3, 13, 3, 3, 5, 37, 5, 3, 11, 13, 5, 7, 3, 5, 3, 17, 7, 37, 3, 11, 5, 23, 13, 3, 13, 5, 3, 3, 3, 47, 73, 29, 23, 13, 3, 5, 11, 5, 3, 37, 17, 19, 5, 7, 3, 13, 17, 3, 61, 11, 13, 5, 3, 19, 13, 3, 3, 5, 61, 53, 13, 3, 37, 23, 13, 7, 3, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..87.

PROG

(PARI) a(n) = {if (n==1, return (2)); p = 3; while(! isprime((prime(n)+p)/2), p = nextprime(p+1)); return (p); } \\ Michel Marcus, Jun 16 2013

CROSSREFS

Cf. A084704.

Sequence in context: A131971 A321882 A281158 * A001269 A201769 A077276

Adjacent sequences:  A100739 A100740 A100741 * A100743 A100744 A100745

KEYWORD

easy,nonn,less

AUTHOR

David Wasserman, Jan 03 2005

STATUS

approved

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Last modified April 6 13:18 EDT 2020. Contains 333276 sequences. (Running on oeis4.)