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

Author

Robert G. Wilson v, Sep 21 2001

Keywords

• nonn

Crossrefs

Cf. A063983, A064213, A064214, A064215, A064217, A064218, A064220.

Programs

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 *)

Extensions

Offset corrected by Georg Fischer, May 01 2022