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Search: id:A134228
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| A134228 |
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Sum of the odd primes <= 2*10^n. |
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+0
3
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| 75, 4225, 277048, 21171189, 1709600811, 142913828920, 12272577818050, 1075207199997332
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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Beginning with 3, compute 10^n sums of odds, less odd composites, for each 10^n.
a(n)=sum(p: p in A000040, 2<p <=2*10^n). a(n)=A007504(k)-2, where k=A049084[A007917(2*10^n)]. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 28 2007
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EXAMPLE
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a(1)=75 because that is the sum of odds (3+5+7+11+13+17+19=75) less composites (9,15,21) under 10^1 (beginning with 3).
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CROSSREFS
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Cf. A134229 A134230.
Sequence in context: A017791 A017738 A075913 this_sequence A110902 A114910 A093275
Adjacent sequences: A134225 A134226 A134227 this_sequence A134229 A134230 A134231
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KEYWORD
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more,nonn
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AUTHOR
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Enoch Haga (Enokh(AT)comcast.net), Oct 14 2007
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EXTENSIONS
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Better definition from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 28 2007
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