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a(n) = Fibonacci(n) mod 100.
5

%I #23 Sep 16 2023 08:39:44

%S 0,1,1,2,3,5,8,13,21,34,55,89,44,33,77,10,87,97,84,81,65,46,11,57,68,

%T 25,93,18,11,29,40,69,9,78,87,65,52,17,69,86,55,41,96,37,33,70,3,73,

%U 76,49,25,74,99,73,72,45,17,62,79,41,20,61,81,42,23,65,88,53,41,94,35,29,64

%N a(n) = Fibonacci(n) mod 100.

%C a(n) = A105472(n)*10 + A003893(n);

%C the sequence is periodic with period 300; all blocks of 60 successive terms contain 20 even and 40 odd numbers, see A003893.

%H Vincenzo Librandi, <a href="/A105471/b105471.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_300">Index entries for linear recurrences with constant coefficients</a>, order 300.

%F a(n) = (a(n-1) + a(n-2)) mod 100 for n>1, a(0) = 0, a(1) = 1.

%t Mod[Fibonacci[Range[0,100]],100] (* _Harvey P. Dale_, Jun 12 2014 *)

%o (Magma) [Fibonacci(n) mod(100): n in [0..75]]; // _Vincenzo Librandi_, Jul 23 2014

%o (Haskell)

%o a105471 n = a105471_list !! n

%o a105471_list = 0 : 1 :

%o zipWith ((flip mod 100 .) . (+)) a105471_list (tail a105471_list)

%o -- _Reinhard Zumkeller_, Aug 06 2014

%o (PARI) a(n)=fibonacci(n%300)%100 \\ _Charles R Greathouse IV_, Oct 07 2015

%Y Cf. A000045, A003893, A105472.

%K nonn,easy

%O 0,4

%A _Reinhard Zumkeller_, Apr 09 2005