cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A054782 Number of primes <= the n-th Fibonacci number.

Original entry on oeis.org

0, 0, 0, 1, 2, 3, 4, 6, 8, 11, 16, 24, 34, 51, 74, 111, 166, 251, 376, 574, 871, 1329, 2033, 3121, 4794, 7396, 11425, 17688, 27426, 42613, 66317, 103298, 161207, 251757, 393790, 616645, 966507, 1516410, 2381429, 3743010, 5888201, 9269519, 14604028
Offset: 0

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Author

Jeff Burch, May 22 2000

Keywords

Crossrefs

Programs

  • Magma
    [0] cat [#PrimesUpTo(Fibonacci(n)): n in [1..42]]; // Vincenzo Librandi, Apr 25 2019
    
  • Maple
    with(combinat): with(numtheory): seq(pi(fibonacci(n)), n = 0 .. 42); # Emeric Deutsch, Jun 24 2009
  • Mathematica
    Table[PrimePi[Fibonacci[n]], {n, 0, 50}] (* Vincenzo Librandi, Apr 25 2019 *)
  • PARI
    a(n) = primepi(fibonacci(n)); \\ Michel Marcus, Apr 25 2019
  • Sage
    [prime_pi(fibonacci(n)) for n in range(0, 43)] # Zerinvary Lajos, Jun 06 2009
    

Formula

a(n) = pi(F(n)) = A000720(A000045(n)). - Vincenzo Librandi, Apr 25 2019

Extensions

More terms from James Sellers, May 23 2000; and N. J. A. Sloane, Nov 07 2000.
Four more terms from Rick L. Shepherd, Dec 06 2004
Three more terms a(40), a(41), a(42) from Harry J. Smith, Dec 16 2008