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Numbers k such that k^3 + k + 91 is prime.
3

%I #16 Sep 08 2022 08:45:31

%S 2,6,9,11,12,17,20,23,27,29,33,38,48,50,53,59,62,68,71,75,81,87,92,93,

%T 101,114,123,129,137,152,153,170,171,176,186,197,198,222,225,246,248,

%U 254,258,263,270,284,288,293,296,297,303,306,309,314,321,324,332,335

%N Numbers k such that k^3 + k + 91 is prime.

%H Daniel Starodubtsev, <a href="/A133160/b133160.txt">Table of n, a(n) for n = 1..10000</a>

%e 2 is in the sequence because 2^3+2+91 = 101 is prime.

%e 93 is in the sequence because 93^3+93+91 = 804541 is prime.

%p a:=proc(n) if isprime(n^3+n+91)=true then n else end if end proc: seq(a(n),n =1..300); # _Emeric Deutsch_, Jan 08 2008

%t Select[Range[400], PrimeQ[ #^3 + # + 91] &] (* _Stefan Steinerberger_, Dec 24 2007 *)

%o (Magma) [ n: n in [0..400] | IsPrime(n^3+n+91) ]; // _Vincenzo Librandi_, Jan 31 2011

%o (PARI) is(n)=isprime(n^3+n+91) \\ _Charles R Greathouse IV_, Jun 06 2017

%Y Cf. A002837.

%K nonn,easy

%O 1,1

%A _Parthasarathy Nambi_, Dec 17 2007

%E More terms from _Stefan Steinerberger_, Dec 24 2007