cp's OEIS Frontend

A194194 Primes of the form n^6 + n^5 + n^4 + n^3 + n^2 + n + 1 where n is nonprime.

%I A194194 #15 Nov 15 2013 14:17:52
%S A194194 7,55987,8108731,321272407,3092313043,4201025641,9684836827,
%T A194194 31401724537,47446779661,83925549247,100343116693,141276239497,
%U A194194 265462278481,438668366137,654022685443,742912017121,2333350772341,3324554405047,4033516174507,4432676798593,9752186278927,14505760086637,15656690128843,16882733081761
%N A194194 Primes of the form n^6 + n^5 + n^4 + n^3 + n^2 + n + 1 where n is nonprime.
%C A194194 Subset of A088550. The n in A018252 for which n^6 + n^5 + n^4 + n^3 + n^2 + n + 1 are prime begin 1, 6, 14, 26, 38, 40.
%H A194194 Harvey P. Dale, <a href="/A194194/b194194.txt">Table of n, a(n) for n = 1..1000</a>
%e A194194 a(1) = 1^6 + 1^5 + 1^4 + 1^3 + 1^2 + 1 + 1 = 7.
%e A194194 a(2) = 6^6 + 6^5 + 6^4 + 6^3 + 6^2 + 6 + 1 = 55987.
%e A194194 a(3) = 14^6 + 14^5 + 14^4 + 14^3 + 14^2 + 14 + 1 = 8108731.
%e A194194 a(4) = 26^6 + 26^5 + 26^4 + 26^3 + 26^2 + 26 + 1 = 321272407.
%t A194194 With[{nn=200},Select[Total[#^Range[0,6]]&/@Complement[Range[nn], Prime[ Range[PrimePi[nn]]]],PrimeQ]] (* _Harvey P. Dale_, Nov 15 2013 *)
%Y A194194 Cf, A000040, A018252, A088548, A185632, A192321.
%K A194194 nonn,easy
%O A194194 1,1
%A A194194 _Jonathan Vos Post_, Dec 20 2012