login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A093765 Numbers n such that 6^n+5^(n-1) is prime. 16
1, 2, 3, 8, 9, 15, 26, 30, 69, 212, 318, 909, 1224, 1946, 2192, 2234, 2978, 3344, 4976, 7947, 8079, 23334, 23624, 55401, 89712 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(26) > 10^5. - Robert Price, Feb 13 2016
LINKS
EXAMPLE
15 is a member since 615+515 = 476288500201 which is a prime number.
MATHEMATICA
Do[ If[ PrimeQ[6^n + 5^(n - 1)], Print[n]], {n, 4000]
PROG
(PARI) is(n)=isprime(6^n+5^(n-1)) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
Sequence in context: A051209 A332481 A331821 * A260020 A104577 A372824
KEYWORD
nonn
AUTHOR
Herman H. Rosenfeld (herm3(AT)pacbell.net), May 17 2004
EXTENSIONS
More terms from Robert G. Wilson v, Jun 18 2004
a(19)-a(25) from Robert Price, Feb 13 2016
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 17 10:44 EDT 2024. Contains 374377 sequences. (Running on oeis4.)