A167518 Least reversible prime (A007500) which is a concatenation of n consecutive primes.

2, 151157, 353359367, 139149151157, 101103107109113, 704517045770459704817048770489, 97101103107109113127, 1519315199152171522715233152411525915263, 382138233833384738513853386338773881, 9319932393379341934393499371937793919397

Offset: 1

Author

M. F. Hasler, Nov 10 2009

Keywords

• nonn
• base

Comments

Here the weaker definition of A007500 is used, but all terms > 2 known so far are also Emirps in the sense of A006567 (i.e. different from their reversal), so it is sufficient to change the first term to 13 in order to have a sequence of "true" emirps.

Is it possible to prove that all terms > 2 are in A006567?

Crossrefs

Cf. A030997, A167517.

Programs

PARI

for(k=1,19,for(i=0,1e9, isprime( eval( p=concat( vector( k,j,Str( prime( i+j )))))) & isprime(eval(concat(vecextract(Vec(p),"-1..1")))) & break); print1(p,", "))

Extensions

Edited by Charles R Greathouse IV, Apr 28 2010

a(9)-a(10) from Donovan Johnson, Sep 25 2011