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A255205 Primes p for which exactly two bases b with 1 < b < p exist such that p is a base b Wieferich prime. 8
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified May 29 04:33 EDT 2020. Contains 334697 sequences. (Running on oeis4.)