A165697 a(n) is the smallest prime p such that all the n numbers reversal(p^k), k<n+1 are primes.

2, 37, 3121, 10429, 10282339, 9835884797, 101740496633

Offset

1,1

Comments

By an interesting approach I was able to find a(7). [From Farideh Firoozbakht, Sep 30 2009]

Links

Table of n, a(n) for n=1..7.

Example

Both numbers reversal(37)=73 & reversal(37^2)=9631 are primes and 37 is the
smallest prime number with this property so a(2)=37.

Crossrefs

Cf. A118212, A118213, A165696, A165698.

Sequence in context: A257995 A234971 A139108 * A320994 A083189 A145798

Adjacent sequences: A165694 A165695 A165696 * A165698 A165699 A165700

Keyword

base,hard,more,nonn

Author

Farideh Firoozbakht, Sep 29 2009

Extensions

a(7) from Farideh Firoozbakht, Sep 30 2009

Status

approved