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%I #18 Apr 05 2017 03:42:10
%S 4,5,7,9,17,30,37,39,42,62,69,72,79,82,85,90,92,95,99,104,110,157,170,
%T 175,177,182,187,194,195,215,217,220,234,239,240,242,255,262,269,272,
%U 277,319,334,339,342,344,359,365,369,370,374,377,387,392,400,417,419,449
%N Numbers k such that k^6 - k^5 - k^4 - k^3 - k^2 - k - 1 is prime.
%H John Cerkan, <a href="/A243300/b243300.txt">Table of n, a(n) for n = 1..10000</a>
%e 4^6 - 4^5 - 4^4 - 4^3 - 4^2 - 4 - 1 = 2731 is prime. Thus 4 is a member of this sequence.
%t Rest@ Select[Range@ 450, Function[n, PrimeQ[Fold[#1 - n^#2 &, n^6, Range@ 5] - 1]]] (* _Michael De Vlieger_, Apr 03 2017 *)
%o (Python)
%o import sympy
%o from sympy import isprime
%o {print(n,end=', ') for n in range(10**3) if isprime(n**6-n**5-n**4-n**3-n**2-n-1)}
%o (PARI) for(n=1,10^3,if(ispseudoprime(n^6-sum(i=0,5,n^i)),print1(n,", ")))
%K nonn
%O 1,1
%A _Derek Orr_, Jun 02 2014
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