login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A064217 Least k such that k*7^n +/- 1 are twin primes. 0

%I

%S 4,6,18,24,138,60,150,720,150,234,138,966,138,420,60,1584,420,60,1830,

%T 1134,162,1080,1482,684,240,10074,3378,3300,2742,984,2400,4050,5262,

%U 3510,3378,960,3612,516,6840,6474,4680,4950,12612,7986,4290,8046,5208

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

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

%Y Cf. A063983.

%K nonn

%O 1,1

%A _Robert G. Wilson v_, Sep 21 2001

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 24 16:33 EST 2020. Contains 331205 sequences. (Running on oeis4.)