OFFSET
1,2
COMMENTS
tau = A000005 is the number of divisors of n.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..423
FORMULA
EXAMPLE
40 is in the sequence because tau(Fibonacci(40)) = tau(102334155) = 64 is square.
MATHEMATICA
Select[Range[150], IntegerQ[Sqrt[DivisorSigma[0, Fibonacci[#]]]] &]
PROG
(PARI) is(n) = issquare(numdiv(fibonacci(n))) \\ Felix Fröhlich, Sep 08 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Mar 15 2010
STATUS
approved