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%I #22 Sep 28 2024 07:55:52
%S 5,7,3,113,3,7,3,5,3,3,373,19,3,11,3,3,3,31,17,3,37,5,3,3,7,3,13,3,5,
%T 3,921259,3,3,5,3,19,79,41,3,3,3,7,3,97,3,5,53,7,3,5,3,3,11,3,3,3,3,
%U 17,139,3,71,3,7,3,157,3,83,13,3,5,3,3,23,11,5,3,3,199
%N a(n) is the least odd prime factor of prime(n)^prime(n)+1.
%H Hugo Pfoertner, <a href="/A376432/b376432.txt">Table of n, a(n) for n = 1..12250</a>
%F a(n) = A078701(A125137(n)). - _Michel Marcus_, Sep 27 2024
%e While almost all terms lie in the range between 3 and (prime(n)+1)/2, there are some notable outliers: a(31) = 921259 with prime(31)=127 (127^127+1=2^7*a(31)*C268), and a(1028)=1528928750837 with prime(1028)=8191 (8191^8191+1=2^13*a(1028)*C32039), Cx being composite with x decimal digits.
%o (PARI) a376432(n) = my(pp=prime(n)^prime(n)+1); forprime (p=3, oo, if(pp%p==0, return(p)))
%Y Cf. A078701, A125137, A376431.
%K nonn
%O 1,1
%A _Hugo Pfoertner_, Sep 27 2024