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A063375 Number of divisors of Fibonacci(n). 31
1, 1, 2, 2, 2, 4, 2, 4, 4, 4, 2, 15, 2, 4, 8, 8, 2, 16, 4, 16, 8, 4, 2, 72, 6, 4, 16, 16, 2, 64, 4, 16, 8, 4, 8, 160, 8, 8, 8, 64, 4, 64, 2, 32, 32, 8, 2, 336, 8, 48, 8, 16, 4, 128, 16, 96, 32, 8, 4, 960, 4, 8, 32, 64, 8, 64, 8, 32, 32, 128, 4, 1536, 4, 16, 48, 32, 16, 128, 4, 512, 128, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1408 (terms 1..1000 from T. D. Noe using Blair Kelly's data)
Florian Luca, Arithmetic Functions of Fibonacci Numbers, The Fibonacci Quarterly, Vol. 37, No. 3 (1999), pp. 265-268.
FORMULA
a(n) = A000005(A000045(n)). - Omar E. Pol, Dec 20 2008
a(n) >= A000045(A000005(n)), with equality if and only if n = 1, 2 or 4 (Luca, 1999). - Amiram Eldar, Jan 12 2022
MATHEMATICA
Table[Length[Divisors[Fibonacci[n]]], {n, 120}] (* Vladimir Joseph Stephan Orlovsky, Jul 01 2011 *)
Table[DivisorSigma[0, Fibonacci[n]], {n, 1, 100}] (* Vaclav Kotesovec, Feb 13 2019 *)
PROG
(PARI) j=[]; for(n=1, 150, j=concat(j, numdiv(fibonacci(n)))); j
(PARI) for (n = 1, 466, write("b063375.txt", n, " ", numdiv(fibonacci(n)))) \\ Harry J. Smith, Aug 20 2009
CROSSREFS
Sequence in context: A072056 A356831 A066012 * A064129 A005137 A222959
KEYWORD
nonn,changed
AUTHOR
Jason Earls, Jul 23 2001
STATUS
approved

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Last modified April 16 22:47 EDT 2024. Contains 371755 sequences. (Running on oeis4.)