OFFSET
0,1
COMMENTS
From the first reference, for numbers up to 10^12 only four strong pseudoprimality tests (with bases 2, 13, 23, 1662803) are necessary for proving primality. Since A074773(19) = 4341937413061, up to 4.10^12 we can use the four bases 2, 3, 5, 7 and if a number n passes the tests, we check if n is equal to a(n mod 1519829 mod 18). If not, n is prime. A unique comparison is used so we have a primality test equally efficient for an interval four times larger. See the Bomfim link.
Terms computed using table by Charles R Greathouse IV. See A074773.
LINKS
Washington Bomfim, A method to find bijections from a set of n integers to {0,1, ... ,n-1}
G. Jaeschke, On strong pseudoprimes to several bases, Mathematics of Computation, 61 (1993), 915-926.
EXAMPLE
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
Washington Bomfim, Mar 14 2012
STATUS
approved