login
A060901
Exact power of 3 that divides the n-th Fibonacci number (sequence A000045).
2
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
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. A038500.
Sequence in context: A365633 A091842 A306346 * A351545 A087612 A260626
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