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A174816 Numbers n such that n^4 + n^2 - 1 is prime. 1
2, 3, 4, 8, 10, 12, 13, 14, 15, 19, 25, 26, 32, 33, 35, 37, 42, 43, 44, 45, 51, 53, 56, 57, 58, 62, 65, 68, 75, 77, 80, 84, 90, 91, 102, 103, 106, 108, 119, 122, 124, 139, 141, 143, 147, 152, 155, 164, 167, 168, 176, 177, 178, 196, 197, 198, 201, 202, 206, 208, 217, 222, 234, 235 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

EXAMPLE

for n=2, a(2) = 3 is in the sequence because 3^4 + 3^2 - 1 = 89 is prime.

MATHEMATICA

lst={}; Do[If[PrimeQ[n^4+n^2-1], AppendTo[lst, n]], {n, 400}]; lst

Select[Range[250], PrimeQ[#^4+#^2-1]&] (* Harvey P. Dale, Aug 24 2011 *)

PROG

(PARI) is(n)=isprime(n^4+n^2-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A047456 A279000 A073465 * A161494 A296161 A121612

Adjacent sequences:  A174813 A174814 A174815 * A174817 A174818 A174819

KEYWORD

nonn,easy

AUTHOR

Michel Lagneau, Dec 01 2010

STATUS

approved

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Last modified October 22 07:48 EDT 2019. Contains 328315 sequences. (Running on oeis4.)