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Search: id:A114323
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| A114323 |
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Largest number whose 5th power has n digits. |
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+0
1
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| 1, 2, 3, 6, 9, 15, 17, 25, 39, 63, 99, 158, 251, 398, 630, 999, 1584, 2511, 3981, 6309, 9999, 15848, 25118, 39810, 63095, 99999, 158489, 251188, 398107, 630957, 999999, 1584893, 2511886, 3981071, 6309573, 9999999, 15848931, 25118864, 39810717
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Note that the rightmost digit of n and n^5 are identical. This is to 5th powers as A061439 is to cubes, and A049416 is to squares.
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FORMULA
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a(n) = ceiling((10^n)^(1/5))-1.
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EXAMPLE
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a(3) = 3 because 3^5 = 243 which has 3 digits, while 4^5 = 1024 has 3 digits.
a(32) = 2511886 because 2511886^5 = 99999914106500508412371346814176 has 32 digits, while 2511887^5 = 100000113160107495177704749808207 has 33 digits.
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CROSSREFS
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Cf. A061439, A049416.
Adjacent sequences: A114320 A114321 A114322 this_sequence A114324 A114325 A114326
Sequence in context: A018060 A115856 A032231 this_sequence A113808 A040040 A086642
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KEYWORD
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easy,nonn
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AUTHOR
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Jonathan Vos Post (jvospost2(AT)yahoo.com), Feb 06 2006
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