login
a(n) = Fibonacci(n) mod 12.
20

%I #58 Sep 08 2022 08:45:12

%S 0,1,1,2,3,5,8,1,9,10,7,5,0,5,5,10,3,1,4,5,9,2,11,1,0,1,1,2,3,5,8,1,9,

%T 10,7,5,0,5,5,10,3,1,4,5,9,2,11,1,0,1,1,2,3,5,8,1,9,10,7,5,0,5,5,10,3,

%U 1,4,5,9,2,11,1,0,1,1,2,3,5,8,1,9,10,7,5,0,5,5,10,3,1,4,5,9,2,11,1,0,1,1

%N a(n) = Fibonacci(n) mod 12.

%C From _Reinhard Zumkeller_, Jul 05 2013: (Start)

%C Sequence has been applied by several composers to 12-tone equal temperament pitch structure. The complete Fibonacci mod 12 system (a set of 10 periodic sequences) exhausts all possible ordered dyads; that is, every possible combination of two pitches is found in these sets.

%C a(A008594(n)) = 0;

%C a(A227144(n)) = 1;

%C a(3*A047522(n)) = 2;

%C a(A017569(n)) = a(2*A016933(n)) = a(4*A016777(n)) = 3;

%C a(2*A017629(n)) = a(3*A017137(n)) = a(6*A004767(n)) = 4;

%C a(A227146(n)) = 5;

%C a(nonexistent) = 6;

%C a(2*A017581(n)) = 7;

%C a(2*A017557(n)) = a(4*A016813(n)) = 8;

%C a(A017617(n)) = a(2*A016957(n)) = a(4*A016789(n)) = 9;

%C a(3*A047621(n)) = 10;

%C a(2*A017653(n)) = 11. (End)

%H Reinhard Zumkeller, <a href="/A089911/b089911.txt">Table of n, a(n) for n = 0..1199</a>

%H Ron Knott, <a href="http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Fibonacci/fib.html">Fibonacci Numbers and the Golden Section</a>

%H M. Renault, <a href="http://webspace.ship.edu/msrenault/fibonacci/fib.htm">The Fibonacci Sequence Modulo M</a>

%H A. P. Shah, <a href="http://www.fq.math.ca/Scanned/6-2/shah.pdf">Fibonacci Sequence Modulo m</a>, Fibonacci Quarterly, Vol.6, No.2 (1968), 139-141.

%H D. D. Wall, <a href="http://www.jstor.org/stable/2309169">Fibonacci series modulo m</a>, Amer. Math. Monthly, 67 (1960), 525-532.

%H <a href="/index/Rec#order_22">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1, 0, -1, 1).

%F Has period of 24, restricted period 12 and multiplier 5.

%F a(n) = (a(n-1) + a(n-2)) mod 12, a(0) = 0, a(1) = 1.

%p with(combinat,fibonacci); A089911 := proc(n) fibonacci(n) mod 12; end;

%t Table[Mod[Fibonacci[n], 12], {n, 0, 100}] (* _Vincenzo Librandi_, Feb 04 2014 *)

%o (Haskell)

%o a089911 n = a089911_list !! n

%o a089911_list = 0 : 1 : zipWith (\u v -> (u + v) `mod` 12)

%o (tail a089911_list) a089911_list

%o -- _Reinhard Zumkeller_, Jul 01 2013

%o (PARI) a(n)=fibonacci(n)%12 \\ _Charles R Greathouse IV_, Feb 03 2014

%o (Magma) [Fibonacci(n) mod 12: n in [0..100]]; // _Vincenzo Librandi_, Feb 04 2014

%Y Cf. A000045, A001175, A003893, A010881.

%K nonn,hear,easy

%O 0,4

%A _Casey Mongoven_, Nov 14 2003

%E More terms from _Ray Chandler_, Nov 15 2003