login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A064214 Least k such that k*5^n +/- 1 are twin primes. 0
4, 6, 6, 24, 42, 42, 18, 198, 42, 54, 96, 84, 522, 240, 48, 228, 708, 732, 660, 132, 528, 390, 78, 1014, 504, 1008, 1134, 504, 708, 582, 894, 516, 2982, 810, 162, 1746, 4758, 1848, 414, 4512, 2928, 1722, 4392, 1104, 1134, 1950, 390, 78, 1500, 300, 60 (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*5^n + 1 ] || ! PrimeQ[ k*5^n - 1 ], k++ ]; Print[ k ], {n, 0, 50} ]

CROSSREFS

Cf. A063983.

Sequence in context: A019090 A145692 A295512 * A019203 A082237 A042976

Adjacent sequences:  A064211 A064212 A064213 * A064215 A064216 A064217

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 21 2001

STATUS

approved

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 November 20 20:28 EST 2019. Contains 329347 sequences. (Running on oeis4.)