Search: id:A049407
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%I A049407
%S A049407 1,2,3,5,6,8,9,12,15,17,18,21,29,30,32,39,41,42,44,48,53,54,56,60,69,
%T A049407 71,74,77,83,87,95,102,104,108,116,117,120,126,131,135,143,144,146,152,
%U A049407 153,155,162,168,177,179,180,186,191,207,212,219,221,225,239,240,243
%N A049407 Numbers n such that n^3+n+1 is prime.
%C A049407 For s = 5,8,11,14,17,20,..., n_s=1+n+n^s is always composite for any 
               n>1. Also for n=1, n_s=3 is a prime for any s. Here we consider the 
               case s=3.
%H A049407 T. D. Noe, <a href="b049407.txt">Table of n, a(n) for n=1..1000</a>
%e A049407 3 is OK because at s=3, n=3, n_s=1+n+n^s=31 is a prime.
%t A049407 lst={};Do[If[PrimeQ[n^3+n+1], AppendTo[lst, n]], {n, 10^3}];lst [From 
               Vladimir Orlovsky (4vladimir(AT)gmail.com), Sep 08 2008]
%Y A049407 Cf. A002384, A075723, A049408.
%Y A049407 Sequence in context: A127936 A096276 A075725 this_sequence A030759 A030709 
               A058588
%Y A049407 Adjacent sequences: A049404 A049405 A049406 this_sequence A049408 A049409 
               A049410
%K A049407 nonn,easy,nice
%O A049407 1,2
%A A049407 N. J. A. Sloane (njas(AT)research.att.com).

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