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A024530
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Numerator of -Sum_{k=1..n} (-1)^k / prime(k).
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9
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1, 1, 11, 47, 727, 7141, 151427, 2366603, 64131559, 1636722341, 57208085801, 1916138684507, 85982424199597, 3392993977055461, 172553478253276697, 8530444564835173531, 535885387802465283059, 30766248305796169627529
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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COMMENTS
| Limit of the fractional values is A078437. [Charles R Greathouse IV, Apr 22, 2011]
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..100
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EXAMPLE
| 1/2, 1/6, 11/30, 47/210, 727/2310, 7141/30030, 151427/510510, ...
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MAPLE
| A024530 := n->numer(add((-1)^(k+1)/ithprime(k), k=1..n));
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MATHEMATICA
| a[n_] := Numerator[ -Total[(-1)^Range[n] / Prime[ Range[n]]]]; Table[a[n], {n, 1, 18}] (* From Jean-François Alcover, Dec 12 2011 *)
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PROG
| (PARI)
a(n)=numerator(-sum(k=1, n, (-1)^k/prime(k)));
vector(33, n, a(n)) /* show terms */
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CROSSREFS
| Denominators are A002110.
Sequence in context: A138362 A191499 A072372 * A117066 A042984 A008780
Adjacent sequences: A024527 A024528 A024529 * A024531 A024532 A024533
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KEYWORD
| nonn,frac,easy,nice
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AUTHOR
| Clark Kimberling (ck6(AT)evansville.edu)
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