A173626 - OEIS

%I #8 Nov 21 2013 12:50:00

%S 2,5,13,17,19,31,37,41,61,71,73,97,101,109,113,127,151,163,181,193,

%T 197,199,211,241,251,257,271,281,307,313,331,337,353,379,397,401,409,

%U 419,421,433,443,449,457,463,487,491,521,541,547,571,577,599,601,613,617

%N Primes p such that p-1 has no prime factors larger than sqrt(p).

%C Intersection of A048098 + 1 and A000040.

%H Charles R Greathouse IV, <a href="/A173626/b173626.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Prime[Range[200]],Max[Transpose[FactorInteger[#-1]][[1]]]<= Sqrt[#]&] (* _Harvey P. Dale_, Feb 21 2012 *)

%o (PARI) print1(2);forprime(p=3,1e3,if(vecmax(factor(p-1)[,1])^2<p,print1(","p)))

%K easy,nice,nonn

%O 1,1

%A _Charles R Greathouse IV_, Nov 08 2010