A325884 Bases b where exactly eight primes p with p < b exist such that p is a base-b Wieferich prime.

1693, 5937, 8201, 9035, 9066, 12943, 13499, 14773, 19065, 24841, 25298, 27382, 28601, 28657, 32074, 37993, 39789, 40276, 41749, 42893, 44425, 46307, 46657, 46924, 47899, 49099, 50471, 52757, 53576, 55737, 56026, 56193, 56645, 57221, 57853, 58445, 59216, 59249

Offset: 1

Author

Felix Fröhlich, May 26 2019

Keywords

• nonn

Comments

Numbers n such that A255920(n) = 8.

Crossrefs

Cf. A255920.

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), A325881 (k=5), A325882 (k=6), A325883 (k=7), A325885 (k=9), A325886 (k=10).

Programs

PARI

is(n) = my(i=0); forprime(p=1, n-1, if(Mod(n, p^2)^(p-1)==1, i++)); i==8