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Search: id:A093151
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| A093151 |
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Number of odd composites 1 mod 4 less than 10^n. |
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+0
3
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| 1, 13, 169, 1890, 20216, 210824, 2167819, 22119495, 224576508, 2272476724, 22940979719, 231196075659, 2326967290816, 23397529216327, 235077715264515, 2360380831212204, 23688221424314913, 237630022857420415, 2382971166402199310, 23889590198849417292
(list; graph; listen)
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OFFSET
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1,2
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FORMULA
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Count odd composites 1 mod 4 less than 10^n
For n>1, a(n) = 25*10^(n-2) - 1 - A091098(n). - Max Alekseyev (maxale(AT)gmail.com), May 30 2007
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EXAMPLE
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Below 10^2 there are 13 odd composites so a(2)=13
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CROSSREFS
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Cf. A093152 A093153 A091295 A091098 A091099.
Sequence in context: A084970 A015961 A045589 this_sequence A014956 A045593 A045597
Adjacent sequences: A093148 A093149 A093150 this_sequence A093152 A093153 A093154
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KEYWORD
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easy,nonn
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AUTHOR
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Enoch Haga (Enokh(AT)comcast.net), Mar 24 2004
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EXTENSIONS
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More terms from Max Alekseyev (maxale(AT)gmail.com), May 30 2007
Extended by Max Alekseyev (maxale(AT)gmail.com), Oct 13 2009
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