The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A062291 Primes p = prime(k) such that k*p - 1 is also a prime. 2

%I #13 Jun 29 2018 19:59:12

%S 3,19,37,43,61,113,251,317,359,409,463,491,557,601,683,827,863,941,

%T 1061,1097,1109,1213,1283,1291,1399,1423,1481,1583,1657,1693,1699,

%U 1811,2069,2267,2297,2531,2687,2741,2851,3011,3181,3271,3323,3331,3347,3373

%N Primes p = prime(k) such that k*p - 1 is also a prime.

%H Harry J. Smith, <a href="/A062291/b062291.txt">Table of n, a(n) for n = 1..1000</a>

%e 19 is in the sequence because 19 is the 8th prime and 8*19 - 1 = 151 is a prime.

%t Select[ Prime[ Range[ 500 ] ], PrimeQ[ # PrimePi[ # ]-1 ]& ]

%o (PARI) for(n=1,200, if(isprime(n*prime(n)-1),print(prime(n))))

%o (PARI) { n=k=0; forprime (p=2, 5*10^5, k++; if (isprime(k*p - 1), write("b062291.txt", n++, " ", p); if (n==1000, break)) ) } \\ _Harry J. Smith_, Aug 04 2009

%K easy,nonn

%O 1,1

%A _Jason Earls_, Jul 02 2001

%E More terms from _Harvey P. Dale_, Jul 05 2001

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 4 15:50 EDT 2023. Contains 365885 sequences. (Running on oeis4.)