This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A060901 #9 Mar 13 2015 23:43:48 %S A060901 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 A060901 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 A060901 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 A060901 Exact power of 3 that divides the n-th Fibonacci number (sequence A000045). %H A060901 Reinhard Zumkeller, <a href="/A060901/b060901.txt">Table of n, a(n) for n = 1..1000</a> %F A060901 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 A060901 a(n) = A038500(A000045(n)). - _Michel Marcus_, Jul 30 2013 %e A060901 a(12) = 9 because the 12th Fibonacci number is 144 and 144 = 9*16. %o A060901 (PARI) a(n) = 3^valuation(fibonacci(n), 3) \\_Michel Marcus_, Jul 30 2013 %o A060901 (Haskell) %o A060901 a060901 = a038500 . a000045 -- _Reinhard Zumkeller_, Feb 04 2015 %Y A060901 Cf. A000045, A060865. %Y A060901 Cf. A038500. %K A060901 nonn,easy %O A060901 1,4 %A A060901 Ahmed Fares (ahmedfares(AT)my-deja.com), May 05 2001 %E A060901 More terms from Larry Reeves (larryr(AT)acm.org), May 07 2001