login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A154894 Fibonacci numbers whose number of proper divisors is prime. 0
8, 21, 34, 55, 377, 610, 987, 4181, 10946, 17711, 46368, 75025, 121393, 1346269, 3524578, 5702887, 9227465, 24157817, 39088169, 63245986, 165580141, 701408733, 1134903170, 1836311903, 7778742049, 12586269025, 20365011074, 53316291173 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

EXAMPLE

8 is member because the number of proper divisors of 8 is 3, a prime number.

MATHEMATICA

Fibonacci[Select[Range[60], PrimeQ[DivisorSigma[0, Fibonacci[ # ]] - 1] &]] [From Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jan 31 2009]

CROSSREFS

Cf. A000045, A152744.

Sequence in context: A134862 A090206 A139590 * A179681 A000567 A124484

Adjacent sequences:  A154891 A154892 A154893 * A154895 A154896 A154897

KEYWORD

nonn

AUTHOR

Omar E. Pol (info(AT)polprimos.com), Jan 25 2009

EXTENSIONS

More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jan 31 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 10:05 EST 2012. Contains 206009 sequences.