cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A244113 Primes p such that f(p), f(f(p)), f(f(f(p))), and f(f(f(f(p)))) are all prime, where f(x) = x^2+3x+1.

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%I A244113 #16 Apr 12 2018 17:08:24
%S A244113 3,1628779,2481113,3260683,3520229,9733123,10671253,10673129,11772809,
%T A244113 36758303,45459353,45594019,58552279,64597903,66539353,74674559,
%U A244113 83471243,96765313,115623929,117479039,131701183,133500553,145010533,163341319,163845719,166410353,167197243,169948223
%N A244113 Primes p such that f(p), f(f(p)), f(f(f(p))), and  f(f(f(f(p)))) are all prime, where f(x) = x^2+3x+1.
%e A244113 p = 3, f(p) = 19,  f(19) = 419, f(419) = 176819 , and  f(176819) = 31265489219 all prime.
%t A244113 Select[Prime[Range[10^7]],AllTrue[Rest[NestList[#^2+3#+1&,#,4]], PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Apr 12 2018 *)
%Y A244113 Subsequence of A250027. Cf. A094210, A153590.
%K A244113 nonn
%O A244113 1,1
%A A244113 _Zak Seidov_, Nov 11 2014