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A130080
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Smallest number whose sixth power has n digits.
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4
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1, 2, 3, 4, 5, 7, 10, 15, 22, 32, 47, 69, 100, 147, 216, 317, 465, 682, 1000, 1468, 2155, 3163, 4642, 6813, 10000, 14678, 21545, 31623, 46416, 68130, 100000, 146780, 215444, 316228, 464159, 681293, 1000000, 1467800, 2154435, 3162278, 4641589
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Powers of sixth root of 10 rounded up.
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FORMULA
| a(n) = ceiling(10^((n-1)/6))
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EXAMPLE
| 6^6 = 46656 has five digits, 7^6 = 117649 has six digits, hence a(6) = 7.
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PROG
| (MAGMA) [ Ceiling(Root(10^(n-1), 6)): n in [1..41] ];
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CROSSREFS
| Cf. A011557 (powers of 10), A017936 (smallest number whose square has n digits), A018005 (smallest number whose cube has n digits), A018074 (smallest number whose fourth power has n digits), A018143 (smallest number whose fifth power has n digits), A130081 to A130084 (smallest number whose seventh ... tenth power has n digits).
Sequence in context: A206739 A107586 A206737 * A057496 A191864 A180348
Adjacent sequences: A130077 A130078 A130079 * A130081 A130082 A130083
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KEYWORD
| nonn,base,easy
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AUTHOR
| Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 07 2007
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