1,1

First term of sequences A065091, A073501, A102325-A102328.

These are the smallest p primes such that 1+p^n are p-smooth, i.e. with all prime-divisors less than p. The same holds for A102325-A102328. For the majority of p's, 1+p^n appear to be not p-smooth, i.e. have large enough greatest prime divisors.

a(8) > 4.5*10^6. - Giovanni Resta, May 02 2017

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

Cf. A000040, A065091, A073501.

Sequence in context: A041949 A222452 A218165 * A331713 A327321 A069143

Adjacent sequences: A102326 A102327 A102328 * A102330 A102331 A102332

nonn

Labos Elemer, Jan 05 2005

a(7)=1507853 from Ray Chandler, Jan 08 2005

approved