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A173180
Numbers k such that k^5-k^4-k^3-k^2-k-1 is prime.
1
4, 6, 8, 14, 18, 20, 24, 26, 28, 32, 40, 42, 50, 58, 62, 68, 72, 100, 104, 120, 122, 140, 150, 174, 184, 192, 210, 234, 240, 260, 266, 278, 288, 300, 306, 326, 346, 366, 404, 432, 444, 460, 464, 466, 470, 484, 488, 512, 516, 526, 538, 556, 562, 564, 570, 584
OFFSET
1,1
COMMENTS
All terms are even. - Robert Israel, Apr 11 2019
LINKS
FORMULA
{k: A125083(k) in A000040}. [R. J. Mathar, Feb 13 2010]
MAPLE
filter:= k -> isprime( k^5-k^4-k^3-k^2-k-1):
select(filter, 2*[$1..500]); # Robert Israel, Apr 11 2019
MATHEMATICA
f[n_]:=n^5-n^4-n^3-n^2-n-1; Select[Range[7! ], PrimeQ[f[ #1]]&]
Select[Range[2, 600, 2], PrimeQ[#^5-Total[#^Range[0, 4]]]&] (* Harvey P. Dale, Sep 26 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved