A242562 - OEIS

A242562

Primes p such that 1000p+1, 1000p+3, 1000p+7 and 1000p+9 are prime.

13, 1447, 5527, 28201, 36217, 75079, 81157, 95911, 187423, 188677, 202327, 210643, 248077, 263323, 282589, 283267, 423043, 466897, 472597, 478189, 478603, 631273, 640261, 695749, 730111, 736279, 806929, 808021, 917641, 964303, 1018177, 1026547, 1064263, 1108489, 1150861

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..35.

EXAMPLE

130001, 130003, 130007 and 130009 are all prime. Thus 13 is a member of this sequence.

PROG

(Python)

import sympy

from sympy import isprime

from sympy import prime

{print(prime(n)) for n in range(1, 10**5) if isprime(1000*prime(n)+1) and isprime(1000*prime(n)+3) and isprime(1000*prime(n)+7) and isprime(1000*prime(n)+9)}

(PARI) for(n=1, 10^5, s=prime(n); if(ispseudoprime(1000*s+1) && ispseudoprime(1000*s+3) && ispseudoprime(1000*s+7) && ispseudoprime(1000*s+9), print(s)));

CROSSREFS

Cf. A236042, A067267.

Sequence in context: A197097 A353030 A064962 * A201357 A220551 A185073

Adjacent sequences: A242559 A242560 A242561 * A242563 A242564 A242565

KEYWORD

nonn

AUTHOR

Derek Orr, May 17 2014

STATUS

approved