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!)
A174821 Numbers n such that n^4 - n^2 - 1 is prime. 0
2, 3, 4, 5, 6, 7, 11, 14, 17, 18, 19, 23, 25, 27, 32, 36, 41, 43, 54, 60, 65, 69, 72, 77, 80, 82, 83, 87, 88, 92, 93, 98, 110, 117, 121, 122, 126, 127, 135, 136, 138, 149, 150, 155, 157, 159, 168, 170, 172, 173, 176, 179, 183, 188, 198 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

EXAMPLE

for n=2, a(2) = 3 and 3^4 - 3^2 - 1 = 71 is prime.

MATHEMATICA

lst={}; Do[If[PrimeQ[n^4-n^2-1], AppendTo[lst, n]], {n, 400}]; lst

PROG

(PARI) is(n)=isprime(n^4-n^2-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A192587 A174323 A103539 * A033086 A059768 A271835

Adjacent sequences:  A174818 A174819 A174820 * A174822 A174823 A174824

KEYWORD

nonn,easy

AUTHOR

Michel Lagneau, Dec 01 2010

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 February 20 04:34 EST 2020. Contains 332063 sequences. (Running on oeis4.)