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A205172 Primes p == 5 (mod 8) such that p + 2 is also prime. 2

%I #13 Nov 25 2019 16:24:52

%S 5,29,101,149,197,269,461,821,1061,1229,1277,1301,1877,1949,1997,2141,

%T 2237,2309,2381,2549,2789,3389,3461,3557,3581,3821,3917,4157,4229,

%U 4421,4517,4637,5021,5477,5501,5741,6197,6269,6701,6869,7349,7589,7757,7877

%N Primes p == 5 (mod 8) such that p + 2 is also prime.

%C The lesser of twin primes == 5 (mod 8).

%H Robert Israel, <a href="/A205172/b205172.txt">Table of n, a(n) for n = 1..10000</a>

%p select(t -> isprime(t) and isprime(t+2), [seq(i,i=5..10000,8)]);# _Robert Israel_, Nov 25 2019

%t Select[ Prime@ Range@ 1000, Mod[#, 8] == 5 && PrimeQ[# + 2] &]

%o (PARI) forprime(p=1, 7900, if(Mod(p, 8)==5 && ispseudoprime(p+2), print1(p, ", "))) \\ _Felix Fröhlich_, Nov 25 2019

%Y Cf. A071695, A205171.

%K easy,nonn

%O 1,1

%A _Robert G. Wilson v_, Jan 22 2012

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)