I asked this list on Saturday about deletable primes. Thanks to everyone who replied. But no one answered my specific question about the largest known deletable prime, so I'm adding these two sequences to the OEIS. Maybe someone would like to extend them! (I will also update them with references to various links that people sent me.) Neil %I A125589 %S A125589 2,13,103,1013,10039 %N A125589 Smallest n-digit base-10 deletable prime. %C A125589 A prime p is a base-b deletable prime if when written in base b it has the property that removing some digit leaves either the empty string or another deletable prime. "Digit" means digit in base b. %C A125589 Deleting a digit cannot leave any leading zeros in the new string. For example, deleting the 2 in 2003 to obtain 003 is not allowed. %Y A125589 Cf. A080608, A096246, A125590. %K A125589 nonn,base,more,new %O A125589 1,1 %A A125589 njas, Jan 07 2007 %I A125590 %S A125590 7,97,997,9973,99929 %N A125590 Largest n-digit base-10 deletable prime. %e A125590 99929 -> 9929 -> 929 -> 29 -> 2. %Y A125590 Cf. A080608, A096246, A125589. %K A125590 nonn,base,more,new %O A125590 1,1 %A A125590 njas, Jan 07 2007