

A058376


When the race of the count of final nonzero digit of n! changes.


0



2, 16, 50, 80, 88, 108, 110, 264, 273, 291, 326, 336, 669, 671, 678, 685, 718, 721, 738, 764, 773, 791, 826, 836, 1433, 1435, 1558, 1560, 1616, 1629, 1636, 1694, 1696, 1764, 1773, 1791, 1826, 1836, 1928, 1935, 1968, 1971, 1988, 2014, 2023, 2041, 2076, 2086
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OFFSET

2,1


LINKS

Table of n, a(n) for n=2..49.
Index entries for sequences related to final digits of numbers


EXAMPLE

a(1) = 2 to start the race. At 15! the number of final twos is 5 and so is the number of eights. But at 16, eights now leads twos, so a(2) = 16 to reflect this fact.
At 1000!, the number of twos is 2509, fours is 2486, sixes is 2494 and finally eights is 2510; for a total of 9999.


MATHEMATICA

f[ n_Integer, m_Integer ] := (c = 0; p = 1; While[ d = Floor[ n/5^p ]; d > 0, c = c + d; p++ ]; Mod[ n!/10^c, m ]); a = Table[ 0, {4} ]; r = 4; Do[ b = f[ n, 10 ]; Switch[ b, 2, a[ [ 1 ] ]++, 4, a[ [ 2 ] ]++, 6, a[ [ 3 ] ]++, 8, a[ [ 4 ] ]++ ]; If[ a[ [ b/2 ] ] > a[ [ r/2 ] ], r = b; Print[ n ] ], {n, 2, 10^4} ]


CROSSREFS

Cf. A045547, A045548, A045549, A045550.
Sequence in context: A063721 A232209 A012180 * A120948 A090453 A006885
Adjacent sequences: A058373 A058374 A058375 * A058377 A058378 A058379


KEYWORD

nonn,base


AUTHOR

Robert G. Wilson v, Dec 19 2000


STATUS

approved



