A182564 Number of primes < Fibonacci(n).

0, 0, 0, 0, 1, 2, 4, 5, 8, 11, 16, 23, 34, 50, 74, 111, 166, 250, 376, 574, 871, 1329, 2033, 3120, 4794, 7396, 11425, 17688, 27426, 42612, 66317, 103298, 161207, 251757, 393790, 616645, 966507, 1516410, 2381429, 3743010, 5888201, 9269519, 14604028, 23023555, 36322186, 57337078, 90565070, 143130478

Offset

0,6

Links

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

Example

Fibonacci(7)=13, there are 5 primes less than 13, so a(7)=5.

Mathematica

Table[If[PrimeQ[Fibonacci[n]], PrimePi[Fibonacci[n]-1], PrimePi[ Fibonacci[ n]]], {n, 0, 50}] (* Harvey P. Dale, Feb 12 2022 *)

Prog

(PARI) a(n) = primepi(fibonacci(n)-1) \\ Michel Marcus, May 13 2013

Crossrefs

Cf. A000040, A000045, A006880, A007053, A028505, A038107, A040014.

Sequence in context: A074824 A039867 A237754 * A288523 A240179 A295032

Adjacent sequences: A182561 A182562 A182563 * A182565 A182566 A182567

Keyword

nonn

Author

Alex Ratushnyak, May 05 2012

Status

approved