The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A174331 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A174331

n such that tau(Fibonacci(n)) is a perfect square.
(history; published version)

#14 by Joerg Arndt at Sun Sep 08 10:05:41 EDT 2019

STATUS

reviewed

approved

#13 by Michel Marcus at Sun Sep 08 09:49:52 EDT 2019

STATUS

proposed

reviewed

#12 by Felix Fröhlich at Sun Sep 08 09:31:53 EDT 2019

STATUS

editing

proposed

#11 by Felix Fröhlich at Sun Sep 08 09:31:23 EDT 2019

PROG

(PARI) is(n) = issquare(numdiv(fibonacci(n))) \\ Felix Fröhlich, Sep 08 2019

STATUS

proposed

editing

#10 by Amiram Eldar at Sun Sep 08 09:12:58 EDT 2019

STATUS

editing

proposed

#9 by Amiram Eldar at Sun Sep 08 08:25:41 EDT 2019

CROSSREFS

Cf. A000005, A000045, A000290, A036436, A063375.

#8 by Amiram Eldar at Sun Sep 08 08:25:00 EDT 2019

LINKS

Amiram Eldar, <a href="/A174331/b174331.txt">Table of n, a(n) for n = 1..423</a>

STATUS

approved

editing

#7 by R. J. Mathar at Mon Jul 09 10:28:35 EDT 2012

STATUS

editing

approved

#6 by R. J. Mathar at Mon Jul 09 10:28:04 EDT 2012

NAME

n such that tau(Fibonacci(n)) is a perfect square.

COMMENTS

tau(n) = A000005 is the number of divisors of n (A000005).

LINKS

Wikipedia, <a href="http://en.wikipedia.org/wiki/Fibonacci_number">Fibonacci number</a>

Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/FibonacciNumber.html">Fibonacci Number</a>

FORMULA

{n: A063375(n) in A000290}. - R. J. Mathar, Jul 09 2012

MATHEMATICA

Select[Range[150], IntegerQ[Sqrt[DivisorSigma[0, Fibonacci[#]]]] &]

CROSSREFS

Cf. A000005, A000045.

STATUS

proposed

editing

#5 by Michel Lagneau at Mon Jul 09 09:17:58 EDT 2012

STATUS

editing

proposed