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A181581 Smallest k such that each of the five factorials (5k)!, (5k+1)!, (5k+2)!, (5k+3)! and (5k+4)! has exactly 10^n trailing 0's. Zero, if no such k exists. 1
1, 9, 81, 801, 8002, 80001, 800001, 8000002, 80000003, 800000003, 8000000003, 80000000003, 800000000002, 8000000000003, 80000000000004, 0, 0, 0, 800000000000000004, 8000000000000000003, 0, 800000000000000000005, 8000000000000000000006, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(n) = A173558(n)/5 or 0.

LINKS

Hiroaki Yamanouchi, Table of n, a(n) for n = 0..100

Index to sequences related to factorial numbers.

CROSSREFS

Cf. A027868, A173558.

Sequence in context: A344253 A338727 A199689 * A137062 A001514 A077364

Adjacent sequences:  A181578 A181579 A181580 * A181582 A181583 A181584

KEYWORD

nonn

AUTHOR

Lekraj Beedassy, Nov 02 2010

EXTENSIONS

a(15)-a(17) corrected and a(18)-a(23) added by Hiroaki Yamanouchi, Oct 06 2014

STATUS

approved

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Last modified November 29 04:38 EST 2021. Contains 349416 sequences. (Running on oeis4.)