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 A090100 Numbers n such that n and the four successive integers produce primes if substituted for x in the polynomial 5x^2+5x+1. See A090562, A090563. Terms show that longer similar chains also exist. 2

%I

%S 1,2,3,13,266,321,322,323,344,641,1324,5436,16700,16701,19857,19858,

%T 28151,28152,30648,31253,32045,45773,48710,50923,52397,57357,57358,

%U 63879,63880,63881,72615,73164,73165,78785,81831,87640,87641,91116

%N Numbers n such that n and the four successive integers produce primes if substituted for x in the polynomial 5x^2+5x+1. See A090562, A090563. Terms show that longer similar chains also exist.

%t Do[s=5*n^2+5*n+1;s1=5*(n+1)^2+5*(n+1)+1; s2=5*(n+2)^2+5*(n+2)+1;s3=5*(n+3)^2+5*(n+3)+1; s4=5*(n+4)^2+5*(n+4)+1; If[PrimeQ[s]&&PrimeQ[s1]&&PrimeQ[s2]&& PrimeQ[s3]&&PrimeQ[s4], Print[n]], {n, 1, 100000}]

%Y Cf. A090562, A090563.

%K easy,nonn

%O 1,2

%A _Labos Elemer_, Dec 12 2003

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Last modified May 10 15:34 EDT 2021. Contains 343775 sequences. (Running on oeis4.)