A068095 All primes dividing each term are Fibonacci numbers.

1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 13, 15, 16, 18, 20, 24, 25, 26, 27, 30, 32, 36, 39, 40, 45, 48, 50, 52, 54, 60, 64, 65, 72, 75, 78, 80, 81, 89, 90, 96, 100, 104, 108, 117, 120, 125, 128, 130, 135, 144, 150, 156, 160, 162, 169, 178, 180, 192, 195, 200

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

Sum_{n>=1} 1/a(n) = Product_{p in A005478} p/(p-1) = 4.12911211011314367889... - Amiram Eldar, Sep 27 2020

Example

26 = 2 * 13 is a term since 2 and 13 are both primes and Fibonacci numbers.

Mathematica

p = Fibonacci[{2, 3, 4, 5, 7, 11, 13}]; Select[Range[p[[-1]]], AllTrue[ FactorInteger[#][[;; , 1]], MemberQ[p, #] &] &] (* Amiram Eldar, Sep 27 2020 *)

Crossrefs

Cf. A000045, A001605, A005478.

Sequence in context: A065108 A094563 A228897 * A064390 A229461 A230709

Adjacent sequences: A068092 A068093 A068094 * A068096 A068097 A068098

Keyword

nonn,easy

Author

Leroy Quet, Mar 22 2002

Extensions

a(1)=1 added and offset corrected by Amiram Eldar, Sep 27 2020

Status

approved