A153213 - OEIS

%I #11 Nov 05 2017 11:54:37

%S 2,47,173,277,727,839,929,1181,1423,1447,1523,1627,1811,1847,1861,

%T 1973,2207,2297,2423,2693,3323,3701,3719,3877,4327,4363,4457,4673,

%U 4691,4903,5227,5573,5821,5927,6173,6221,6323,6473,6577,6653,7027,7103,7477,7823

%N Primes p such that both p-2 and p+2 are not squarefree.

%H John Cerkan, <a href="/A153213/b153213.txt">Table of n, a(n) for n = 1..10000</a>

%t lst={};Do[p=Prime[n];If[ !SquareFreeQ[p-2]&&!SquareFreeQ[p+2],AppendTo[lst,p]],{n,7!}];lst

%o (PARI) is(n)=isprime(n) && !issquarefree(n-2) && !issquarefree(n+2) \\ _Charles R Greathouse IV_, Nov 05 2017

%Y Cf. A049282, A049097, A039787, A075432, A153207, A153208, A153209, A153210.

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Dec 20 2008