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A115396 Smallest prime p such that p-/+2n are semiprimes. 0
23, 29, 71, 17, 59, 37, 71, 41, 67, 71, 43, 109, 59, 67, 173, 83, 89, 151, 103, 89, 127, 101, 131, 113, 127, 109, 131, 113, 127, 193, 157, 157, 181, 179, 229, 163, 193, 191, 211, 223, 223, 239, 241, 211, 211, 211, 271, 281, 241, 241, 263, 307, 307, 373, 293 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Cf. A063643 Primes p such that p+/-2 are semiprimes, A117328 Primes p such that p+/-4 are semiprimes.

LINKS

Table of n, a(n) for n=1..55.

EXAMPLE

a(100)=571 because 571-2*100=371=7*53 (semiprime), 571+2*100=771=3*257 (semiprime).

CROSSREFS

Cf. A063643.

Sequence in context: A157677 A092518 A110584 * A180538 A227217 A229176

Adjacent sequences:  A115393 A115394 A115395 * A115397 A115398 A115399

KEYWORD

nonn

AUTHOR

Zak Seidov, Mar 08 2006

STATUS

approved

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Last modified October 25 20:39 EDT 2014. Contains 248557 sequences.