login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A284437 Number of primes between n and 2^n inclusive. 1
0, 1, 2, 3, 4, 9, 15, 28, 50, 93, 168, 305, 559, 1023, 1894, 3506, 6536, 12245, 22993, 43383, 82017, 155603, 295939, 564155, 1077862, 2063680, 3957800, 7603544, 14630834, 28192741, 54400018, 105097555, 203280210, 393615795, 762939100, 1480206268, 2874398504, 5586502337 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..47

EXAMPLE

a(0) = 0 because there are 0 primes between 0 and 2^0.

a(5) = 9 because there are 9 primes between 5 and 2^5: 5, 7, 11, 13, 17, 19, 23, 29, 31 (we count the boundary of the interval in this case).

MATHEMATICA

Join[{0}, f[n_]:=PrimePi[2^n] - PrimePi[n-1]; Array[f, 37]]

PROG

(MAGMA) [0] cat [#PrimesInInterval(n, 2^n): n in [1..28]];

CROSSREFS

Cf. A000720, A007053, A035250, A060715, A284275.

Sequence in context: A084080 A124753 A248647 * A049909 A096781 A232055

Adjacent sequences:  A284434 A284435 A284436 * A284438 A284439 A284440

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Mar 27 2017

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 15 14:32 EDT 2019. Contains 327078 sequences. (Running on oeis4.)