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A165753
Number of trailing zeros in sequence of factorials of Fibonacci numbers.
1
0, 0, 0, 0, 1, 1, 2, 4, 7, 13, 20, 34, 56, 93, 150, 244, 396, 643, 1043, 1689, 2733, 4425, 7161, 11587, 18754, 30344, 49100, 79449, 128552, 208007, 336563, 544573, 881140, 1425715, 2306860, 3732583, 6039449, 9772038, 15811490, 25583533, 41395029
OFFSET
1,7
COMMENTS
a(n) is the number of zeros at rightmost place of F(n)!
REFERENCES
C. Suriano, Miniature Matematiche, Il rosone, 2009, pp. 149-152.
LINKS
FORMULA
a(n) = A027868(A000045(n))
a(n) = k * phi^n + O(n), for k = 1/sqrt(80).
EXAMPLE
F(7)!=13!=6227020800 which ends with 2 zeros; therefore a(7)=2.
MATHEMATICA
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 *)
CROSSREFS
Sequence in context: A347703 A112997 A037032 * A347779 A369520 A266650
KEYWORD
nonn
AUTHOR
Carmine Suriano, Sep 26 2009
EXTENSIONS
Extended and edited by Charles R Greathouse IV, Mar 23 2010
STATUS
approved