OFFSET
1,3
COMMENTS
a(n) is the greatest k such that 2^k does not exceed prime(n). - David James Sycamore, Sep 14 2021
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
FORMULA
MAPLE
map(ilog2, select(isprime, [2, seq(2*i+1, i=1..1000)])); # Robert Israel, Jun 08 2015
MATHEMATICA
Floor[Log[2, Prime[Range[105]]]] (* data *) (* parameter changed by Hartmut F. W. Hoft, Jun 02 2015 *)
PROG
(PARI) a(n) = logint(prime(n), 2); \\ Michel Marcus, Sep 17 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Reinhard Zumkeller, Sep 06 2004
STATUS
approved