A134100 - OEIS

%I #36 Oct 27 2021 12:59:39

%S 29,37,53,59,67,79,89,97,127,137,149,157,163,173,179,191,211,223,239,

%T 251,257,263,269,277,293,307,331,337,347,359,367,373,379,389,397,409,

%U 419,431,439,449,457,479,487,499,509,521,541,547,557,563,569,577,587

%N Primes p > 3 such that neither p-2 nor p-4 are prime.

%C Upper primes after a prime gap of 6 or larger (Union of A031925, A031927, A031929, ...) - _R. J. Mathar_, Mar 15 2012

%H Bill McEachen, <a href="/A134100/b134100.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) ~ n log n. - _Charles R Greathouse IV_, Oct 27 2021

%e 29 is a term because 29 follows the odd nonprime 27 which in turn follows the odd nonprime 25.

%t Select[Range[5,1000,2],PrimeQ[#]&&!PrimeQ[#-2]&&!PrimeQ[#-4]&] (* _Vladimir Joseph Stephan Orlovsky_, Feb 03 2012 *)

%o (PARI) forprime(p=5,600,if(!isprime(p-2) && !isprime(p-4), print1(p,", "))); \\ _Joerg Arndt_, Oct 27 2021

%o (PARI) list(lim)=my(v=List(),p=23); forprime(q=29,lim, if(q-p>4, listput(v,q)); p=q); Vec(v) \\ _Charles R Greathouse IV_, Oct 27 2021

%Y Cf. A007510, A083370, A124582, A134099, A134101, A073830.

%K easy,nonn

%O 1,1

%A _Enoch Haga_, Oct 08 2007

%E Name corrected by _Michel Marcus_ and _Amiram Eldar_, Oct 27 2021