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Twin primes ending in 3.
4

%I #8 Feb 14 2017 10:36:49

%S 3,13,43,73,103,193,283,313,433,463,523,643,823,883,1033,1063,1093,

%T 1153,1303,1453,1483,1723,1873,1933,2083,2113,2143,2383,2593,2713,

%U 2803,3253,3373,3463,3583,3673,3823,3853,4003,4093,4243,4273,4423,4483,4723,4933

%N Twin primes ending in 3.

%H Omar E. Pol, <a href="http://www.polprimos.com">Determinacion geometrica de los numeros primos y perfectos</a>

%p isA181604 := proc(p)

%p if isprime(p) and (isprime(p-2) or isprime(p+2)) then

%p if modp(p,10) = 3 then

%p true;

%p else

%p false;

%p end if ;

%p else

%p false;

%p end if;

%p end proc: # _R. J. Mathar_, Feb 14 2017

%t Select[Prime@Range@700, Mod[ #, 10] == 3 && (PrimeQ[ # - 2] || PrimeQ[ # + 2]) &] (* _Robert G. Wilson v_, Nov 06 2010 *)

%Y Cf. A001097, A181603, A181605, A181606.

%K base,nonn

%O 1,1

%A _Omar E. Pol_, Nov 01 2010

%E More terms from _Robert G. Wilson v_, Nov 06 2010