OFFSET
1,1
LINKS
Chris Caldwell, The First 1,008 Twin Primes.
EXAMPLE
3557 is a prime produced by concatenating twin primes (3,5) and (5,7).
355711131719 is a prime produced by concatenating twin primes (3,5), (5,7), (11,13) and (17,19).
MATHEMATICA
tw = Select[ Prime@ Range@100000, PrimeQ[ # + 2] &]; tw = Flatten /@ IntegerDigits@ Transpose[{tw, tw + 2}]; t = {}; Do[p = FromDigits@ Flatten@ Table[ tw[[i]], {i, n}]; If[ PrimeQ[p], Print[p]], {n, 1090}] (* Robert G. Wilson v *)
CROSSREFS
KEYWORD
hard,more,nonn,bref,base
AUTHOR
Parthasarathy Nambi, Jun 09 2005
STATUS
approved