|
%I #11 Jan 10 2020 13:04:50
%S 0,0,0,0,1,1,2,4,7,13,20,34,56,93,150,244,396,643,1043,1689,2733,4425,
%T 7161,11587,18754,30344,49100,79449,128552,208007,336563,544573,
%U 881140,1425715,2306860,3732583,6039449,9772038,15811490,25583533,41395029
%N Number of trailing zeros in sequence of factorials of Fibonacci numbers.
%C a(n) is the number of zeros at rightmost place of F(n)!
%D C. Suriano, Miniature Matematiche, Il rosone, 2009, pp. 149-152.
%H Harvey P. Dale, <a href="/A165753/b165753.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = A027868(A000045(n))
%F a(n) = k * phi^n + O(n), for k = 1/sqrt(80).
%e F(7)!=13!=6227020800 which ends with 2 zeros; therefore a(7)=2.
%t zOF[n_Integer?Positive]:=Module[{maxpow=0},While[5^maxpow<=n,maxpow++];Plus@@Table[Quotient[n,5^i],{i,maxpow-1}]];zOF[#]&/@ Fibonacci[ Range[ 50]] (* _Harvey P. Dale_, Jan 10 2020 *)
%K nonn
%O 1,7
%A _Carmine Suriano_, Sep 26 2009
%E Extended and edited by _Charles R Greathouse IV_, Mar 23 2010
|
