OFFSET
2,4
COMMENTS
LINKS
Felix Fröhlich, Table of n, a(n) for n = 2..10000
R. Crandall, K. Dilcher and C. Pomerance, A search for Wieferich and Wilson primes, Mathematics of Computation, 66 (1997), 433-449.
FORMULA
a(n) = min(b(n) mod p, -b(n) mod p) where p = prime(n) and b(n) = Sum_{i=1..ceiling((p-1)/4)} (2i-1)^(p-2). - Daniel Chen, Sep 01 2022
PROG
(PARI) a(n, p=prime(n))=abs(centerlift(Mod(2, p^2)^((p-1)/2))\/p)
apply(p->a(0, p), primes(100)[2..100]) \\ Charles R Greathouse IV, Jun 15 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, May 28 2015
STATUS
approved