|
|
A185192
|
|
Number of primes less than 2^n.
|
|
3
|
|
|
0, 2, 4, 6, 11, 18, 31, 54, 97, 172, 309, 564, 1028, 1900, 3512, 6542, 12251, 23000, 43390, 82025, 155611, 295947, 564163, 1077871, 2063689, 3957809, 7603553, 14630843, 28192750, 54400028, 105097565, 203280221, 393615806, 762939111, 1480206279, 2874398515
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
This sequence differs from A007053 in the offset and in that the latter includes 1 (since the prime 2 is equal to 2^1, not less than it).
Number of primes with at most n bits.
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
a(7) = 31 because prime(31) = 127, prime(32) = 131, and 127 < 2^7 < 131.
|
|
MATHEMATICA
|
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,hard
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|