A089923 Largest prime in the reverse concatenation of the first n consecutive prime numbers when that concatenation is a prime.

5, 17, 89, 383

Offset

5,1

Links

Table of n, a(n) for n=5..8.

Example

53 is the reverse concatenation of the consecutive primes 3 and 5. 53 is prime.

Prog

(PARI) revprime2(n) = { y=3; forprime(x=5, n, y=concat(Str(x), Str(y)); z=eval(y); if(ispseudoprime(z), print(x", "z)) ) }

Crossrefs

Sequence in context: A153499 A012782 A026685 * A145041 A212291 A307176

Adjacent sequences: A089920 A089921 A089922 * A089924 A089925 A089926

Keyword

nonn,base

Author

Cino Hilliard, Jan 11 2004

Extensions

Edited by T. D. Noe, Oct 30 2008

Status

approved