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A282378 Primes of the form (p^2 + q^2)/2 such that (p^4 + q^4)/2 is prime, where p and q are primes. 1

%I

%S 17,89,97,149,157,229,241,769,937,1109,1117,1129,1249,1549,1753,2161,

%T 2221,2389,3301,3769,4129,4261,4801,4909,5113,5449,5569,5869,6121,

%U 6469,7369,7621,7681,8089,8329,8389,8761,9649,10009,10429,11161,11941,12241,12409

%N Primes of the form (p^2 + q^2)/2 such that (p^4 + q^4)/2 is prime, where p and q are primes.

%H Charles R Greathouse IV, <a href="/A282378/b282378.txt">Table of n, a(n) for n = 1..10000</a>

%o (PARI) list(lim)=my(v=List(),p2,p4,t); lim\=1; if(lim<9,lim=9); forprime(p=3,sqrtint(2*lim-9), p2=p^2; p4=p2^2; forprime(q=3, min(sqrtint(2*lim-p2),p), if(isprime(t=(p2+q^2)/2) && isprime((p4+q^4)/2), listput(v, t)))); Set(v) \\ _Charles R Greathouse IV_, Feb 14 2017

%Y Subsequence of A103739.

%K nonn

%O 1,1

%A _Thomas Ordowski_ and _Altug Alkan_, Feb 13 2017

%E More terms from _Arkadiusz Wesolowski_, Feb 13 2017

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Last modified September 20 08:10 EDT 2021. Contains 347577 sequences. (Running on oeis4.)