A064221 Least k such that k*12^n +/- 1 are twin primes.

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

Offset

0,1

Links

Table of n, a(n) for n=0..50.

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, A064213, A064214, A064215, A064217, A064218, A064220.

Sequence in context: A193793 A301510 A085471 * A378592 A229672 A298568

Adjacent sequences: A064218 A064219 A064220 * A064222 A064223 A064224

Keyword

nonn

Author

Robert G. Wilson v, Sep 21 2001

Extensions

Offset corrected by Georg Fischer, May 01 2022

Status

approved