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Primes p such that p == 1 (mod A001414(p-1)) and p == 1 (mod A001414(p+1)).
2

%I #10 Nov 30 2020 01:05:23

%S 17,31,151,241,577,3001,3571,4801,12097,21121,23761,28513,61441,65521,

%T 77761,113023,126001,171697,174721,178753,193441,244901,287281,364801,

%U 582427,616897,677321,976501,1016401,1425601,1431847,2015441,2080801,2483713,2672671,3089371,4321931,4667921,5177761

%N Primes p such that p == 1 (mod A001414(p-1)) and p == 1 (mod A001414(p+1)).

%C Members p of A339180 such that p == 1 (mod A001414(p-1)).

%H Robert Israel, <a href="/A339181/b339181.txt">Table of n, a(n) for n = 1..198</a>

%e a(3) = 151 is in the sequence because 151 is prime, A001414(150)=2+3+5+5=15, A001414(152)=2+2+2+19=25, 151 == 1 (mod 15) and 151 == 1 (mod 25).

%p spf:= n -> add(t[1]*t[2], t=ifactors(n)[2]):

%p select(p -> isprime(p) and p mod spf(p-1) = 1 and p mod spf(p+1) = 1, [seq(i, i=3..6*10^6, 2)]);

%Y Cf. A001414, A339180.

%K nonn

%O 1,1

%A _J. M. Bergot_ and _Robert Israel_, Nov 26 2020

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Last modified September 22 22:30 EDT 2024. Contains 376140 sequences. (Running on oeis4.)