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A087031 Numbers n such that 2p-n is prime, p is the smallest prime > n. 1
1, 3, 9, 15, 27, 31, 39, 33, 31, 39, 47, 57, 61, 69, 63, 61, 69, 75, 91, 99, 93, 91, 99, 105, 115, 135, 117, 123, 115, 135, 141, 147, 151, 159, 167, 177, 183, 195, 185, 189, 183, 195, 199, 213, 217, 225, 219, 217, 225, 237, 245, 251, 257, 267, 271, 279, 273, 271 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

FORMULA

a(n)=2p-n, p is the smallest prime > n

EXAMPLE

3 is a term because smallest prime >3 is 5 and 2*5-3=7 is prime.

CROSSREFS

Cf. A087030.

Sequence in context: A085046 A138495 A055927 * A089632 A082897 A147516

Adjacent sequences:  A087028 A087029 A087030 * A087032 A087033 A087034

KEYWORD

easy,nonn

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com), Jul 31 2003

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Last modified February 17 17:35 EST 2012. Contains 206061 sequences.