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A255922
Bases b for which exactly one Wieferich prime p with p < b exists such that p is a base-b Wieferich prime.
11
5, 7, 8, 9, 10, 13, 21, 22, 23, 24, 25, 27, 29, 30, 31, 32, 33, 35, 38, 42, 43, 44, 45, 46, 48, 50, 54, 55, 60, 61, 64, 70, 74, 77, 78, 79, 85, 91, 94, 98, 100, 105, 110, 112, 113, 115, 120, 122, 126, 128, 131, 132, 133, 136, 138, 141, 150, 151, 152, 153, 154
OFFSET
1,1
COMMENTS
Numbers b such that A255920(n) = 1.
LINKS
PROG
(PARI) is(n) = my(i=0); forprime(p=1, n-1, if(Mod(n, p^2)^(p-1)==1, i++); if(i > 1, return(0))); i==1
CROSSREFS
Cf. A255920.
Cf. bases b with exactly k base-b Wieferich primes less than b: A255921 (k=0), A255923 (k=2), A255924 (k=3), A255925 (k=4), A325881 (k=5), A325882 (k=6), A325883 (k=7), A325884 (k=8), A325885 (k=9), A325886 (k=10).
Sequence in context: A261917 A111339 A273786 * A241028 A171097 A166460
KEYWORD
nonn
AUTHOR
Felix Fröhlich, Mar 12 2015
STATUS
approved