# [seqfan] Prime concatenation of n consecutive primes

zak seidov zakseidov at yahoo.com
Sun Jul 11 12:58:36 CEST 2010

```Not submitted, just for curious...
Zak

2,2,5,2,7,113,29,107,211,691,23,11,5,71,277,181,13,
307,43,223,43,167,31,23,151,29,67,383,19,53,53,277,
541,37,103,127,947,79,4409,1699,13,73,31,107,751,
1187,1069,859,67,229,293,47,1303,2909,1319,701,241,
19,3313,4349,271,229,4073,47,5843,1193,349,47,199,
937,317,53,1021,263,5419,4591,613,9787,937,241,
997,271,1787,2591,6551,181,859,853,4483,983,71,
47,601,8609,3331,2081,521,3691,139,2297

Smallest primes p such that concatenation of  n consecutive primes starting with p is prime.

2 (=prime), 23  (concatenation of 2 consecutive primes = prime), 5711  (concatenation of 3 consecutive primes = prime), 235711   (concatenation of 4 consecutive primes = prime)

For primes that are concatenations of 2..6 consecutive primes see A030461, A030469, A030473, A086041, A099727.
See also A030997 Smallest prime which is a concatenation of n consecutive primes,
from where I took the pari code due M. F. Hasler.

BTW correct a(28) in b030997.txt is:
383389397401409419421431433439443449457461463467479487491499503509521523541547557563

```