|
|
A317979
|
|
Numbers k such that k^4 + k^3 + k^2 + 1 is prime.
|
|
1
|
|
|
2, 4, 6, 8, 14, 22, 26, 32, 36, 54, 82, 96, 98, 108, 116, 120, 124, 132, 144, 152, 162, 164, 166, 182, 226, 240, 244, 246, 252, 254, 264, 266, 274, 276, 312, 314, 322, 328, 330, 352, 364, 368, 372, 382, 406, 410, 420, 422, 428, 430, 432, 438, 456
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
The numbers in the sequence are all even numbers.
For k = 11*m - 4, (k^4 + k^3 + k^2 + 1)/11 is an integer, so there is no number of the form k = 11*m - 4 in the sequence.
|
|
LINKS
|
|
|
EXAMPLE
|
2^4 + 2^3 + 2^2 + 1 = 29 is prime, so 2 is in the sequence.
|
|
MATHEMATICA
|
Select[Range[0, 1000], PrimeQ[#^4 + #^3 + #^2 + 1] &]
|
|
PROG
|
(PARI) for(n=1, 1000, if(ispseudoprime(n^4 + n^3 + n^2 + 1), print1(n, ", ")))
(Magma) [n: n in [0..700] |IsPrime(n^4 + n^3 + n^2 + 1)]; // Vincenzo Librandi, Sep 08 2018
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|