A227907 - OEIS

%I #21 Jun 22 2020 23:30:58

%S 2,3,5,7,11,19,37,67,71,79,137,191,229,277,283,317,347,359,397,409,

%T 431,457,461,479,499,577,691,739,743,757,787,811,829,839,967,1009,

%U 1061,1087,1091,1109,1153,1193,1279,1327,1373,1429

%N Primes p such that 4*p - q is also prime, where p, q are consecutive primes.

%H Robert Israel, <a href="/A227907/b227907.txt">Table of n, a(n) for n = 1..10000</a>

%p isA227907 := proc(n)

%p     local q;

%p     if isprime(n) then

%p         q := nextprime(n) ;

%p         isprime(4*n-q) ;

%p     else

%p         false;

%p     end if;

%p end proc:

%p for n from 1 to 3000 do

%p     if isA227907(n) then

%p         printf("%d,",n) ;

%p     end if;

%p end do: # _R. J. Mathar_, Oct 14 2013

%o (PARI) isokp(p) = isprime(p) && isprime(4*p - nextprime(p+1)); \\ _Michel Marcus_, Oct 13 2013

%K nonn

%O 1,1

%A _Irina Gerasimova_, Oct 12 2013