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A241189
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Numerator of Sum_{i=1..n} 1/(prime(i)*prime(i+1)).
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5
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1, 7, 11, 127, 1693, 29243, 561623, 13019431, 379503437, 11809225121, 438235268123, 18007758091069, 775817745542929, 36524284093223105, 1938403609207158571, 2160165866032831207, 131893095784520401909, 8844093116997411126541, 628373208972323386101329, 45900898298568589325230523
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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1/6, 7/30, 11/42, 127/462, 1693/6006, 29243/102102, 561623/1939938, 13019431/44618574, 379503437/1293938646, 11809225121/40112098026, 438235268123/1484147626962, ...
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MAPLE
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g:= n-> add(1/(ithprime(i)*ithprime(i+1)), i=1..n);
t1:=[seq(g(n), n=1..20)];
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MATHEMATICA
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Table[Numerator@ Sum[1/(Prime[i + 1] Prime@ i), {i, n}], {n, 20}] (* Michael De Vlieger, Jan 27 2016 *)
Accumulate[1/#&/@(Times@@@Partition[Prime[Range[25]], 2, 1])]//Numerator (* Harvey P. Dale, Mar 14 2023 *)
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CROSSREFS
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KEYWORD
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nonn,frac
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AUTHOR
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STATUS
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approved
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