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A124521 Numbers k such that 16*k - 1 and 16*k + 1 are twin primes. 4
12, 15, 27, 72, 93, 117, 132, 162, 168, 195, 198, 210, 258, 267, 300, 327, 330, 345, 435, 468, 642, 765, 813, 855, 903, 912, 960, 978, 993, 1128, 1143, 1182, 1290, 1350, 1353, 1365, 1392, 1398, 1440, 1632, 1680, 1713, 1737, 1797, 1848, 1860, 1947, 1953, 1962 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

EXAMPLE

12 is in the sequence since 16*12 - 1 = 191 and 16*12 + 1 = 193 are twin primes.

MAPLE

A124521:=n->`if`(isprime(16*n-1) and isprime(16*n+1), n, NULL): seq(A124521(n), n=1..2000); # Wesley Ivan Hurt, Oct 10 2014

MATHEMATICA

Select[Range[2000], And @@ PrimeQ[{-1, 1} + 16# ] &] (* Ray Chandler, Nov 16 2006 *)

CROSSREFS

Cf. A040040, A045753, A002822, A124065, A124518, A124519, A124520, A124522, A063983.

Sequence in context: A050480 A290508 A063604 * A134221 A179148 A194234

Adjacent sequences:  A124518 A124519 A124520 * A124522 A124523 A124524

KEYWORD

nonn

AUTHOR

Artur Jasinski, Nov 04 2006

EXTENSIONS

Extended by Ray Chandler, Nov 16 2006

STATUS

approved

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Last modified April 14 07:59 EDT 2021. Contains 342946 sequences. (Running on oeis4.)