A174331 - OEIS

A174331

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

1, 2, 6, 8, 9, 10, 14, 18, 19, 20, 22, 26, 27, 28, 30, 31, 32, 34, 40, 41, 42, 52, 53, 55, 59, 61, 64, 66, 71, 73, 74, 77, 79, 85, 87, 89, 92, 93, 94, 95, 97, 99, 101, 107, 109, 113, 115, 116, 117, 120, 121, 123, 125, 127, 128, 129, 130, 133, 135, 138, 143, 146, 147, 149

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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

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

EXAMPLE

40 is in the sequence because tau(Fibonacci(40)) = tau(102334155) = 64 is square.

MATHEMATICA