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A085637 Numbers n such that n*prime(n) -/+ 1 are twin primes. 3
2, 30, 72, 144, 312, 336, 510, 690, 990, 1122, 1254, 1272, 1410, 2082, 2376, 2508, 2586, 2664, 2802, 3060, 3096, 3180, 3432, 3510, 3684, 4062, 4506, 5526, 5790, 6174, 7224, 8064, 8388, 9078, 9390, 9504, 10698, 10794, 10884, 10992, 11046, 11334 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A086172 and A086173. See also A086174, A086175, A086176, A086177.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

EXAMPLE

n=30 is a term because 30*prime[30]+/1=3390+/1 are twin primes.

MATHEMATICA

Select[Range[15000], PrimeQ[ # Prime[ # ] - 1] && PrimeQ[ # Prime[ # ] + 1] &]

PROG

(MAGMA) [n: n in [1..11500] | IsPrime(n*NthPrime(n) - 1) and IsPrime(n*NthPrime(n) + 1) ]; // Vincenzo Librandi, Oct 05 2012

CROSSREFS

Cf. A086172, A086173, A086174, A086175, A086176, A086177.

Sequence in context: A134644 A244379 A189100 * A193177 A157870 A285991

Adjacent sequences:  A085634 A085635 A085636 * A085638 A085639 A085640

KEYWORD

easy,nonn

AUTHOR

Zak Seidov, Jul 11 2003

STATUS

approved

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Last modified September 23 12:53 EDT 2020. Contains 337310 sequences. (Running on oeis4.)