

A046035


Numbers n such that the concatenation of the first n primes (A019518) is a prime.


10




OFFSET

1,2


COMMENTS

The primes themselves (A069151) are sometimes called SmarandacheWellin primes.
No others with n <= 10400.  Eric W. Weisstein, Mar 01 2004


REFERENCES

R. Crandall and C. Pomerance, Prime Numbers: A Computational Perspective, Springer, NY, 2001; see p. 72. [The 2002 printing states incorrectly that 719 is a term.]


LINKS

Table of n, a(n) for n=1..8.
M. Fleuren, Smarandache Concatenated Primes.
Eric Weisstein's World of Mathematics, Integer Sequence Primes
Eric Weisstein's World of Mathematics, Consecutive Number Sequences


EXAMPLE

4 is a term since 2357 is a prime. [Corrected by Ed Murphy (emurphy42(AT)socal.rr.com), May 15 2007]


MATHEMATICA

a = ""; Do[a = StringJoin[a, ToString[ Prime[n]]]; If[ PrimeQ[ ToExpression[a ]], Print[n]], {n, 1, 1429}]
nn=1500; With[{prs=Prime[Range[nn]]}, Flatten[Position[Table[ FromDigits[ Flatten[ IntegerDigits/@Take[prs, n]]], {n, nn}], _?PrimeQ]]] (* Harvey P. Dale, Dec 17 2013 *)


CROSSREFS

Cf. A019518, A033308, A069151. A046284(n) = prime(a(n)).
Sequence in context: A006314 A009595 A018493 * A134710 A009073 A012561
Adjacent sequences: A046032 A046033 A046034 * A046036 A046037 A046038


KEYWORD

nonn,base,nice


AUTHOR

Eric W. Weisstein


STATUS

approved



