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A350401 Primes p such that if q is the next prime, p*q mod (A004086(p)+A004086(q)) is prime.

%I A350401 #12 Dec 30 2021 17:32:23
%S A350401 3,5,7,11,13,23,29,31,53,59,71,73,83,89,101,107,109,127,137,149,163,
%T A350401 173,181,191,193,211,223,227,233,239,257,271,277,281,283,307,317,367,
%U A350401 373,389,409,419,431,449,461,463,467,479,491,509,521,523,547,577,587,593,607,613,631,641,643,653,659
%N A350401 Primes p such that if q is the next prime, p*q mod (A004086(p)+A004086(q)) is prime.
%H A350401 Robert Israel, <a href="/A350401/b350401.txt">Table of n, a(n) for n = 1..10000</a>
%e A350401 a(6) = 23 is a member because it is prime, the next prime is 29, and 23*29 mod (32+92) = 667 mod 124 = 47 is prime.
%p A350401 revdigs:= proc(n) local L,i,m;
%p A350401   L:= convert(n,base,10); m:= nops(L);
%p A350401   add(L[i]*10^(m-i),i=1..m)
%p A350401 end proc:
%p A350401 q:= 2: qr:= 2:
%p A350401 R:= NULL: count:= 0:
%p A350401 while count < 100 do
%p A350401   p:=q; pr:= qr;
%p A350401   q:= nextprime(p); qr:= revdigs(q); s:= p*q mod (pr+qr);
%p A350401   if isprime(s) then
%p A350401      R:= R, p; count:= count+1;
%p A350401   fi
%p A350401 od:
%p A350401 R;
%Y A350401 Cf. A004086.
%K A350401 nonn,base
%O A350401 1,1
%A A350401 _J. M. Bergot_ and _Robert Israel_, Dec 28 2021