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A045524 n! has initial digit '5'. 18
7, 21, 38, 46, 61, 66, 81, 119, 137, 144, 150, 165, 189, 196, 206, 209, 221, 224, 235, 243, 248, 253, 258, 279, 292, 340, 342, 353, 362, 383, 413, 429, 440, 488, 508, 529, 540, 584, 597, 611, 630, 651, 662, 679, 685, 704, 711, 718, 725, 732, 764, 782, 812 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

n such that A000030(A000142(n))=5. Robert Israel, Feb 07 2017

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Index entries for sequences related to factorial numbers

MAPLE

filter:= proc(t) local tf;

tf:= t!;

floor(tf/10^ilog10(tf)) = 5

end proc:

select(filter, [$1..1000]); # Robert Israel, Feb 07 2017

MATHEMATICA

Select[ Range[ 850 ], IntegerDigits[ #! ] [[1]] == 5 & ]

PROG

(PARI) isok(n) = digits(n!)[1] == 5; \\ Michel Marcus, Feb 08 2017

CROSSREFS

For factorials with initial digit d (1 <= d <= 9) see A045509, A045510, A045511, A045516, A045517, A045518, A282021, A045519; A045520, A045521, A045522, A045523, A045525, A045526, A045527, A045528, A045529.

Cf. A000030, A000142.

Sequence in context: A208543 A009475 A063292 * A125228 A024837 A205864

Adjacent sequences:  A045521 A045522 A045523 * A045525 A045526 A045527

KEYWORD

nonn,base

AUTHOR

Jeff Burch

STATUS

approved

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Last modified October 22 06:02 EDT 2018. Contains 316432 sequences. (Running on oeis4.)