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.

Showing 1-2 of 2 results.

A069108 Primes of the form F(k)+k where F(k) is the k-th Fibonacci number.

Original entry on oeis.org

2, 3, 5, 7, 29, 43, 317839, 3524611, 39088207
Offset: 1

Views

Author

Benoit Cloitre, Apr 06 2002

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Table[Fibonacci[k] + k, {k, 1, 40}], PrimeQ] (* Amiram Eldar, Jun 04 2022 *)

Formula

A002062 INTERSECT A000040. - R. J. Mathar, Apr 24 2017
a(n) = A002062(A175404(n)). - Amiram Eldar, Jun 04 2022

Extensions

a(10), a 169-digit number, has been certified prime with Primo. - Rick L. Shepherd, Apr 26 2002
a(11), a 343-digit number, has been certified prime with Primo. - Charles R Greathouse IV, Feb 15 2011

A270821 Numbers n such that F(n) - n is a prime, where F(n) denotes the n-th Fibonacci number.

Original entry on oeis.org

6, 8, 16, 26, 28, 76, 148, 159, 808, 848, 916, 1143, 4036, 4959, 43239, 73432, 98716, 144039, 146132
Offset: 1

Views

Author

Paolo P. Lava, Mar 30 2016

Keywords

Examples

			fibonacci(6) - 6 = 8 - 6 = 2 that is a prime;
fibonacci(8) - 8 = 21 - 8 = 13 that is a prime.
		

Crossrefs

Programs

  • Maple
    with(combinat): P:=proc(q) local n;
    for n from 0 to q do
    if isprime(fibonacci(n)-n) then print(n); fi; od; end: P(10^5);
  • Mathematica
    Select[Range[150000],PrimeQ[Fibonacci[#]-#]&] (* Harvey P. Dale, May 03 2018 *)
  • PARI
    lista(nn) = {for(n=1, nn, if(ispseudoprime(fibonacci(n)-n), print1(n, ", ")));} \\ Altug Alkan, Mar 30 2016

Extensions

a(15)-a(19) from Giovanni Resta, Apr 14 2016
Showing 1-2 of 2 results.