A255205 Primes p for which exactly two bases b with 1 < b < p exist such that p is a base b Wieferich prime.

11, 71, 127, 131, 163, 211, 229, 313, 347, 349, 353, 359, 367, 463, 509, 599, 607, 631, 647, 673, 797, 827, 829, 977, 1021, 1061, 1087, 1109, 1123, 1187, 1327, 1381, 1399, 1429, 1453, 1483, 1493, 1499, 1523, 1531, 1549, 1553, 1607, 1613, 1619, 1621, 1657, 1669

Offset

1,1

Comments

p = prime(n) such that A242830(n) = 2.

Links

Table of n, a(n) for n=1..48.

Prog

(PARI) forprime(p=1, , b=2; i=0; while(b < p, if(Mod(b, p^2)^(p-1)==1, i++); b++); if(i==2, print1(p, ", ")))

Crossrefs

Cf. A255203, A255204, A255206, A255207, A255208, A255209, A255210.

Sequence in context: A071746 A205812 A162568 * A117047 A089720 A333408

Adjacent sequences: A255202 A255203 A255204 * A255206 A255207 A255208

Keyword

nonn

Author

Felix Fröhlich, Feb 17 2015

Status

approved