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A114306 Numbers k such that Fibonacci(k) has more divisors than k does. 1
9, 12, 15, 16, 18, 19, 20, 21, 24, 25, 27, 28, 30, 31, 32, 33, 35, 36, 37, 38, 39, 40, 41, 42, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 84, 85, 86, 87, 88, 89, 90, 91 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Jinyuan Wang, Table of n, a(n) for n = 1..500

EXAMPLE

15 is in the sequence because 610 (=Fibonacci(15)) has more divisors than 15.

MAPLE

with(combinat): with(numtheory): b:=proc(n) if tau(fibonacci(n))>tau(n) then n else fi end: seq(b(n), n=1..100); # Emeric Deutsch, May 13 2006

MATHEMATICA

Select[Range[1, 100], DivisorSigma[0, Fibonacci[#]] > DivisorSigma[0, #] &] (* Vaclav Kotesovec, Feb 13 2019 *)

PROG

(PARI) isok(n) = numdiv(fibonacci(n)) > numdiv(n); \\ Michel Marcus, Feb 13 2019

CROSSREFS

Cf. A000005, A000045, A063375.

Sequence in context: A259313 A170951 A044859 * A009188 A138299 A050435

Adjacent sequences:  A114303 A114304 A114305 * A114307 A114308 A114309

KEYWORD

nonn

AUTHOR

Shyam Sunder Gupta, Feb 05 2006

STATUS

approved

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Last modified February 27 07:07 EST 2020. Contains 332300 sequences. (Running on oeis4.)