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!)
A162294 Numbers k such that k^3-k^2-k-1 is prime. 4
4, 6, 8, 12, 16, 22, 28, 34, 44, 50, 54, 56, 58, 76, 78, 88, 110, 112, 118, 134, 138, 156, 162, 166, 168, 170, 188, 190, 200, 204, 208, 210, 226, 230, 236, 244, 250, 268, 274, 302, 310, 314, 322, 324, 340, 344, 356, 364, 368, 378, 382, 390, 398, 400, 420, 424 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

FORMULA

k^3-k^2-k-1 = A162295(n), where k=a(n).

Sum_{i=1..n} a(i) = Sum_{i=1..n} i * ( pi(i^3 - i^2 - i - 1) - pi(i^3 - i^2 - i - 2) ). - Wesley Ivan Hurt, May 24 2013

EXAMPLE

k=4 is in the sequence because 4^3-4^2-4-1=43 is prime.

k=6 is in the sequence because 6^3-6^2-6-1=173 is prime.

MATHEMATICA

lst={}; Do[p=n^3-n^2-n-1; If[PrimeQ[p], AppendTo[lst, n]], {n, 2, 6!}]; lst

CROSSREFS

Cf. A087908, A111501, A162291, A162293, A162295 (corresponding primes).

Sequence in context: A062554 A020225 A310663 * A211026 A090989 A161219

Adjacent sequences:  A162291 A162292 A162293 * A162295 A162296 A162297

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jun 30 2009

EXTENSIONS

Edited by R. J. Mathar, Jul 02 2009

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 March 28 14:24 EDT 2020. Contains 333089 sequences. (Running on oeis4.)