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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A224468 Primes of the form 7^n - n. 4
47, 117643, 5764793, 13841287189, 15286700631942576193765185769276826357, 36703368217294125441230211032033660188753 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The next term is too big to display. Corresponding n are given in A224470.

LINKS

Table of n, a(n) for n=1..6.

MAPLE

A224468:=proc(q) local n;

for n from 1 to q do if isprime(7^n-n) then print(7^n-n); fi; od; end:

A224468(100); # Paolo P. Lava, Apr 19 2013

MATHEMATICA

Select[Table[7^k - k, {k, 2, 1000, 2}], PrimeQ] (* Bruno Berselli, Apr 07 2013 *)

CROSSREFS

Cf. A081296, A224420, A224451, A024076, A224470.

Sequence in context: A210818 A093940 A237512 * A328364 A087533 A292071

Adjacent sequences:  A224465 A224466 A224467 * A224469 A224470 A224471

KEYWORD

nonn

AUTHOR

Alex Ratushnyak, Apr 06 2013

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 January 18 05:18 EST 2021. Contains 340250 sequences. (Running on oeis4.)