A206097 Fibonacci numbers F with 2 distinct prime divisors, and F+2 or F-2 also with 2 distinct prime divisors.

55, 4181, 17711, 121393, 5702887

Offset

1,1

Links

Table of n, a(n) for n=1..5.

Example

55=5*11; (55+2)=3*19, 4181=37*113; (4181+2)=47*89

Mathematica

Select[Fibonacci[Range[300]], Last/@FactorInteger[#]=={1, 1} && (Last/@FactorInteger[#+2]=={1, 1} || Last/@FactorInteger[#-2]=={1, 1})&]

Crossrefs

Cf. A000045

Sequence in context: A060077 A035323 A250833 * A103918 A013537 A056567

Adjacent sequences: A206094 A206095 A206096 * A206098 A206099 A206100

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Feb 03 2012

Status

approved