A060901 Exact power of 3 that divides the n-th Fibonacci number (sequence A000045).

1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 27, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 27, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1

Offset

1,4

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Formula

If n is not divisible by 4 then a(n) = 1, if n = 4 * 3^k * m where m is not divisible by 3 then a(n) = 3^(k+1).

a(n) = A038500(A000045(n)). - Michel Marcus, Jul 30 2013

Example

a(12) = 9 because the 12th Fibonacci number is 144 and 144 = 9*16.

Prog

(PARI) a(n) = 3^valuation(fibonacci(n), 3) \\Michel Marcus, Jul 30 2013
(Haskell)
a060901 = a038500 . a000045  -- Reinhard Zumkeller, Feb 04 2015

Crossrefs

Cf. A000045, A060865.

Cf. A038500.

Sequence in context: A365633 A091842 A306346 * A351545 A087612 A260626

Adjacent sequences: A060898 A060899 A060900 * A060902 A060903 A060904

Keyword

nonn,easy

Author

Ahmed Fares (ahmedfares(AT)my-deja.com), May 05 2001

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), May 07 2001

Status

approved