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!)
A268065 Integers k such that 2^k + 3^k + 5^k + k is prime. 2
0, 1, 3, 7, 19, 33, 1363, 6663 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Next term, if it exists, is greater than 30000. - Vaclav Kotesovec, Jan 26 2016

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

k=3: 2^3+3^3+5^3+3 = 163.

MATHEMATICA

Select[Range[0, 2000], PrimeQ[2^# + 3^# + 5^# + #] &] (* Vaclav Kotesovec, Jan 25 2016 *)

PROG

(PARI) lista(nn) = for(n=0, nn, if(ispseudoprime(2^n + 3^n + 5^n + n), print1(n, ", "))); \\ Altug Alkan, Jan 25 2016

CROSSREFS

Cf. A076515, A268067.

Sequence in context: A112633 A113916 A227502 * A049490 A112391 A127928

Adjacent sequences:  A268062 A268063 A268064 * A268066 A268067 A268068

KEYWORD

nonn,more

AUTHOR

Emre APARI, Jan 25 2016

EXTENSIONS

a(7) from Vaclav Kotesovec, Jan 25 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 30 19:15 EDT 2021. Contains 346359 sequences. (Running on oeis4.)