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A161360
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Decimal expansion of Product_p p#/(p#-1).
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4
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2, 4, 9, 5, 8, 0, 6, 5, 1, 4, 0, 5, 9, 8, 3, 8, 2, 7, 2, 7, 7, 4, 9, 7, 9, 2, 0, 4, 9, 3, 0, 1, 5, 3, 4, 3, 7, 2, 6, 1, 0, 3, 7, 9, 3, 7, 6, 1, 5, 5, 0, 7, 7, 9, 6, 3, 9, 6, 9, 1, 6, 5, 3, 8, 9, 5, 1, 3, 5, 7, 2, 2, 2, 6, 4, 9, 6, 5, 6, 5, 6, 9, 0, 4, 5, 5, 5, 7, 0, 3, 4, 8, 5, 6, 1, 3, 5, 4, 0, 0, 1, 6, 2, 5, 2
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OFFSET
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1,1
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COMMENTS
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By p# we mean the primorial number which is the product of the primes less than or equal to p.
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LINKS
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FORMULA
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This number is equal to Sum_k 1/A025487(k).
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EXAMPLE
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2/1 * 6/5 * 30/29 * ... = 2.495806514059838272774979204930153...
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MATHEMATICA
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RealDigits[Times@@(#/(#-1)&/@Rest[FoldList[Times, 1, Prime[Range[100]]]]), 10, 120][[1]] (* Harvey P. Dale, Mar 15 2015 *)
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PROG
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(PARI) h(n)=local(p, pl, r); p=2; pl=1; r=1.; while(p<n, pl*=p; r/=(1-1./pl); p=nextprime(p+1)); r
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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