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.

A102326 Primes p such that the largest prime divisor of p^4+1 is less than p.

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%I A102326 #17 Aug 09 2019 22:12:24
%S A102326 10181,14051,18979,25253,57173,58013,60101,62497,65951,66541,69457,
%T A102326 75931,82241,82261,84229,87721,88339,88819,91499,92333,95917,99523,
%U A102326 105557,107747,109229,118493,118927,137339,146291,155399,157019
%N A102326 Primes p such that the largest prime divisor of p^4+1 is less than p.
%C A102326 Primes in A309562. - _Robert Israel_, Aug 09 2019
%H A102326 Robert Israel, <a href="/A102326/b102326.txt">Table of n, a(n) for n = 1..1000</a>
%e A102326 p = 10181, 1+p^4 = 10743894862923122 = 2*17*1657*4657*5113*8009, so the largest prime factor is 8009 < p = 10181.
%p A102326 filter:= proc(p) max(numtheory:-factorset(p^4+1)) < p end proc:
%p A102326 select(filter, [seq(ithprime(i),i=1..20000)]); # _Robert Israel_, Aug 09 2019
%t A102326 <<NumberTheory`NumberTheoryFunctions` Select[Prime[Range[15000]], Max[PrimeFactorList[1 + #^4]] < # &] (* _Ray Chandler_, Jan 08 2005 *)
%t A102326 Select[Prime[Range[15000]],FactorInteger[#^4+1][[-1,1]]<#&] (* _Harvey P. Dale_, Feb 27 2017 *)
%o A102326 (PARI) isok(p) = isprime(p) && (vecmax(factor(p^4+1)[,1]) < p); \\ _Michel Marcus_, Jul 09 2018
%Y A102326 Cf. A000040, A065091, A073501, A309562.
%K A102326 nonn
%O A102326 1,1
%A A102326 _Labos Elemer_, Jan 05 2005
%E A102326 Extended by _Ray Chandler_, Jan 08 2005