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A072220 a(n)-th factorial is the smallest factorial containing exactly n 9's, or 0 if no such number exists. 8
12, 11, 21, 29, 34, 46, 36, 59, 79, 75, 0, 70, 82, 90, 95, 97, 112, 89, 105, 96, 134, 130, 127, 165, 142, 149, 144, 145, 161, 163, 182, 189, 160, 178, 139, 180, 206, 192, 224, 214, 188, 215, 226, 207, 218, 267, 283, 261, 268, 262, 240, 280, 234, 285, 343, 277 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

It is conjectured that a(11)=0 since no factorial < 10000 contained just eleven nines.

LINKS

Table of n, a(n) for n=1..56.

EXAMPLE

a(2)=11 since 11th factorial, i.e., 11!=39916800, contains exactly two 9's.

MATHEMATICA

Do[k = 1; While[ Count[IntegerDigits[k! ], 9] != n, k++ ]; Print[k], {n, 1, 60}]

CROSSREFS

Cf. A072232, A072208, A072204, A072200, A072199, A072178, A072177, A072163, A072124.

Sequence in context: A070560 A019330 A086045 * A171986 A254717 A195748

Adjacent sequences:  A072217 A072218 A072219 * A072221 A072222 A072223

KEYWORD

base,nonn

AUTHOR

Shyam Sunder Gupta, Jul 30 2002

EXTENSIONS

Edited and extended by Robert G. Wilson v, Jul 31 2002

STATUS

approved

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Last modified September 17 03:42 EDT 2021. Contains 347478 sequences. (Running on oeis4.)