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%I #5 May 26 2019 15:00:46
%S 99,161,226,293,313,424,521,557,577,606,632,649,753,757,821,874,901,
%T 925,937,1030,1033,1081,1108,1116,1149,1342,1443,1457,1524,1549,1557,
%U 1586,1618,1668,1777,1921,1927,1929,1993,2039,2060,2061,2069,2077,2098,2141,2269
%N Bases b where exactly five primes p with p < b exist such that p is a base-b Wieferich prime.
%C Numbers n such that A255920(n) = 5.
%o (PARI) is(n) = my(i=0); forprime(p=1, n-1, if(Mod(n, p^2)^(p-1)==1, i++)); i==5
%Y Cf. A255920.
%Y Cf. bases b with exactly k base-b Wieferich primes less than b: A255921 (k=0), A255922 (k=1), A255923 (k=2), A255924 (k=3), A255925 (k=4), A325882 (k=6), A325883 (k=7), A325884 (k=8), A325885 (k=9), A325886 (k=10).
%K nonn
%O 1,1
%A _Felix Fröhlich_, May 26 2019