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A241190
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Denominator of Sum_{i=1..n} 1/(prime(i)*prime(i+1)).
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5
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6, 30, 42, 462, 6006, 102102, 1939938, 44618574, 1293938646, 40112098026, 1484147626962, 60850052705442, 2616552266334006, 122977956517698282, 6517831695438008946, 7255699434544198638, 442597665507196116918, 29654043588982139833506, 2105437094817731928178926, 153696907921694430757061598
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OFFSET
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1,1
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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[Denominator@ Sum[1/(Prime[i + 1] Prime@ i), {i, n}], {n, 20}] (* Michael De Vlieger, Jan 27 2016 *)
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PROG
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(PARI) a(n) = denominator(sum(k=1, n, 1/(prime(k)*prime(k+1)))); \\ Michel Marcus, Jan 27 2016
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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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