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Search: id:A109693
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| A109693 |
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Decimal expansion of sum_n=1^inf 1/sigma(n)^2. |
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+0
1
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| 1, 3, 0, 6, 4, 5, 6, 5, 1, 2, 0
(list; cons; graph; listen)
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OFFSET
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1,2
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FORMULA
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product_p sum_k=0^inf 1/sigma(p^k)^2
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EXAMPLE
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1.3064565120...
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PROGRAM
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(PARI) N=1000000000 prodeuler(p=2, N, sum(k=1, 200/log(p), if(k==1, 1., 1./((p^k-1)/(p-1))^2)))*(1+1/N/log(N))
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CROSSREFS
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Cf. Sigma function A000203.
Adjacent sequences: A109690 A109691 A109692 this_sequence A109694 A109695 A109696
Sequence in context: A088162 A133170 A062542 this_sequence A004606 A019808 A056459
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KEYWORD
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cons,more,nonn
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AUTHOR
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Frank Adams-Watters (FrankTAW(AT)netscape.net), Aug 07 2005
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