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!)
A125881 Numbers k for which k^3+k^2-1 is prime. 15
2, 4, 5, 6, 9, 11, 12, 14, 19, 22, 25, 26, 27, 29, 32, 34, 36, 37, 40, 44, 47, 49, 55, 60, 62, 64, 65, 69, 70, 71, 81, 82, 84, 89, 95, 97, 106, 107, 114, 119, 121, 125, 127, 132, 139, 140, 141, 144, 147, 155, 159, 161, 165, 172, 174, 179, 184, 190, 201, 204 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Generating polynomial belongs to the family of irreducible polynomials (or trinomials) of the form x^n+x^(n-1)-1.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harvey P. Dale)

MATHEMATICA

Do[If[PrimeQ[x^3 + x^2 - 1], Print[x]], {x, 1, 100}]

Select[Range[250], PrimeQ[#^3 + #^2 - 1] &] (* Harvey P. Dale, Jan 20 2015 *)

PROG

(PARI) isok(n) = isprime(n^3+n^2-1); \\ Michel Marcus, Nov 08 2013

CROSSREFS

Cf. A045546, A125882, A125883, A125884, A125885.

Sequence in context: A050011 A030303 A047315 * A287370 A089969 A166944

Adjacent sequences:  A125878 A125879 A125880 * A125882 A125883 A125884

KEYWORD

nonn

AUTHOR

Artur Jasinski, Dec 14 2006

EXTENSIONS

More terms from Michel Marcus, Nov 08 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 October 17 00:35 EDT 2021. Contains 348048 sequences. (Running on oeis4.)