A232726 Primes p such that the concatenation 123456789p is prime.

23, 29, 167, 191, 199, 257, 311, 409, 419, 433, 457, 563, 587, 601, 653, 761, 769, 809, 881, 947, 1013, 1069, 1091, 1153, 1163, 1187, 1223, 1259, 1283, 1307, 1433, 1489, 1511, 1723, 1787, 1789, 1913, 1993, 2039, 2137

Offset

1,1

Comments

Primes in A232725.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

1163 is in this sequence because 1163 and 1234567891163 are prime.

Mathematica

Select[Prime[Range[500]], PrimeQ[FromDigits[Join[Range[9], IntegerDigits[ #]]]]&] (* Harvey P. Dale, Nov 26 2014 *)

Prog

(Python)
from sympy import isprime
for n in range(5000):
    if isprime(n) and isprime(int("123456789" + str(n))):
        print(n, end=', ') # simplified by Derek Orr, Nov 27 2014
(PARI) forprime(p=1, 5000, if(isprime(eval(concat("123456789", Str(p)))), print1(p, ", "))) \\ Derek Orr, Nov 27 2014

Crossrefs

Cf. A232725, A104914, A104915.

Sequence in context: A180538 A227217 A229176 * A029541 A068714 A344127

Adjacent sequences: A232723 A232724 A232725 * A232727 A232728 A232729

Keyword

nonn,base,less

Author

Derek Orr, Nov 29 2013

Status

approved