A064217 Least k such that k*7^n +/- 1 are twin primes.

4, 6, 18, 24, 138, 60, 150, 720, 150, 234, 138, 966, 138, 420, 60, 1584, 420, 60, 1830, 1134, 162, 1080, 1482, 684, 240, 10074, 3378, 3300, 2742, 984, 2400, 4050, 5262, 3510, 3378, 960, 3612, 516, 6840, 6474, 4680, 4950, 12612, 7986, 4290, 8046, 5208

Offset

0,1

Links

Table of n, a(n) for n=0..46.

Mathematica

Do[ k = 1; While[ ! PrimeQ[ k*7^n + 1 ] || ! PrimeQ[ k*7^n - 1 ], k++ ]; Print[ k ], {n, 0, 50} ]

Crossrefs

Cf. A063983, A064213, A064214, A064215, A064218, A064220, A064221.

Sequence in context: A219190 A337617 A120391 * A026623 A026689 A138276

Adjacent sequences: A064214 A064215 A064216 * A064218 A064219 A064220

Keyword

nonn

Author

Robert G. Wilson v, Sep 21 2001

Extensions

Offset corrected by Georg Fischer, May 01 2022

Status

approved