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%I A286094 #49 Jul 31 2017 03:22:46
%S A286094 1,12,22,24,28,30,40,44,50,62,63,68,74,77,85,94,99,110,117,118,120,
%T A286094 122,129,134,143,145,154,162,164,165,172,175
%N A286094 Nonprime numbers n such that n^4 + n^3 + n^2 + n + 1 is prime.
%C A286094 A065509 Union {this sequence} = A049409.
%C A286094 The corresponding prime numbers n^4 + n^3 + n^2 + n + 1 = 11111_n are in A193366; these Brazilian primes, except 5 which is not Brazilian, belong to A085104 and A285017.
%H A286094 R. J. Cano, <a href="/load/view.php?a=aHR0cDovL29laXMub3JnL0EyODYwOTQvYjI4NjA5NC50eHQ">Table of n, a(n) for n = 1..10000</a>
%H A286094 Bernard Schott, <a href="/load/view.php?a=aHR0cDovL29laXMub3JnL0ExMjUxMzQvYTEyNTEzNC5wZGY">Les nombres brésiliens</a>, Quadrature, no. 76, avril-juin 2010, pages 30-38.
%e A286094 12 is in the sequence because 12^4 + 12^3 + 12^2 + 12 + 1 = 11111_12 = 22621, which is prime.
%t A286094 Select[Range@ 414, And[! PrimeQ@ #, PrimeQ[Total[#^Range[0, 4]]]] &] (* _Michael De Vlieger_, May 03 2017 *)
%o A286094 (PARI) isok(n)=if(n==1,5,if(ispseudoprime(n), 0, isprime(fromdigits([1, 1, 1, 1, 1], n))));
%o A286094 getfirstterms(n)={my(L:list, c:small); L=List(); c=0; forstep(k=1, +oo, 1, if(isok(k), listput(L, k); if(c++==n, break))); return(Vec(L))} \\ _R. J. Cano_, May 09 2017
%Y A286094 Cf. A049409, A065509, A085104, A088548, A125134, A190527, A193366, A285017.
%K A286094 nonn
%O A286094 1,2
%A A286094 _Bernard Schott_, May 02 2017

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