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A064221 Least k such that k*12^n +/- 1 are twin primes. 0
4, 1, 3, 19, 33, 4, 165, 35, 150, 35, 205, 35, 63, 435, 48, 4, 223, 399, 388, 149, 125, 86, 335, 491, 565, 876, 73, 250, 85, 526, 217, 139, 557, 676, 488, 629, 592, 1290, 2110, 366, 140, 2461, 6198, 6476, 2033, 751, 7258, 2054, 2275, 1345, 445 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..51.

MATHEMATICA

Do[ k = 1; While[ ! PrimeQ[ k*12^n + 1 ] || ! PrimeQ[ k*12^n - 1 ], k++ ]; Print[ k ], {n, 0, 50} ]

lktpQ[n_]:=Module[{c=12^n, k=1}, While[!AllTrue[k*c+{1, -1}, PrimeQ], k++]; k]; Array[lktpQ, 60, 0] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jul 21 2015 *)

CROSSREFS

Cf. A063983.

Sequence in context: A193793 A301510 A085471 * A229672 A298568 A152890

Adjacent sequences:  A064218 A064219 A064220 * A064222 A064223 A064224

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 21 2001

STATUS

approved

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Last modified November 18 07:39 EST 2018. Contains 317279 sequences. (Running on oeis4.)