OFFSET
2,1
COMMENTS
Payam numbers yield many primes of the form k*2^n+1 (Proth primes) and k*2^n-1.
LINKS
Robert Smith, A coordinated search for primes in the Payam number series.
Eric Weisstein's World of Mathematics, Payam Number
EXAMPLE
E_{-}(4) = 45 because 45 is the smallest odd integer k such that for every nonnegative integer n, k*2^n-1 is not divisible by 3, 5, or 7, the only primes p for which the multiplicative order of 2 mod p is less than or
equal to 4.
CROSSREFS
KEYWORD
nonn
AUTHOR
David Terr, Jun 11 2003
STATUS
approved