|
%I #9 Mar 13 2015 23:43:48
%S 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,
%T 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,
%U 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
%N Exact power of 3 that divides the n-th Fibonacci number (sequence A000045).
%H Reinhard Zumkeller, <a href="/A060901/b060901.txt">Table of n, a(n) for n = 1..1000</a>
%F 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).
%F a(n) = A038500(A000045(n)). - _Michel Marcus_, Jul 30 2013
%e a(12) = 9 because the 12th Fibonacci number is 144 and 144 = 9*16.
%o (PARI) a(n) = 3^valuation(fibonacci(n), 3) \\_Michel Marcus_, Jul 30 2013
%o (Haskell)
%o a060901 = a038500 . a000045 -- _Reinhard Zumkeller_, Feb 04 2015
%Y Cf. A000045, A060865.
%Y Cf. A038500.
%K nonn,easy
%O 1,4
%A Ahmed Fares (ahmedfares(AT)my-deja.com), May 05 2001
%E More terms from Larry Reeves (larryr(AT)acm.org), May 07 2001
|
