login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms are even. - Robert Israel, Apr 11 2019

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

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]]&]

CROSSREFS

Cf. A002328, A008864, A162294, A173179

Sequence in context: A050902 A320125 A110974 * A200077 A256137 A116897

Adjacent sequences:  A173177 A173178 A173179 * A173181 A173182 A173183

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Feb 11 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 May 21 00:51 EDT 2019. Contains 323428 sequences. (Running on oeis4.)