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A119534 Largest prime divisor of numerator of the n-th Artin's product. 2
5, 19, 41, 109, 109, 271, 271, 271, 811, 929, 929, 929, 929, 2161, 2161, 2161, 3659, 4421, 4969, 4969, 4969, 4969, 4969, 9311, 10099, 10099, 10099, 10099, 10099, 16001, 17029, 17029, 19181, 22051, 22051, 22051, 22051, 22051, 22051, 22051, 32579 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

Artin's constant (A005596) is equal to Product[1-1/(Prime[k]*(Prime[k]-1)),{k,1,Infinity}]. n-th Artin's product is Product[1-1/(Prime[k]*(Prime[k]-1)),{k,1,n}]. a(n) is prime from A091568 of the form p^2-p-1, where p is prime from A091567.

LINKS

Table of n, a(n) for n=2..42.

Eric Weisstein's World of Mathematics, Artin's Constant.

FORMULA

a(n) = Max[FactorInteger[Numerator[Product[1-1/(Prime[k]*(Prime[k]-1)),{k,1,n}]]]].

MATHEMATICA

Table[Max[FactorInteger[Numerator[Product[1-1/(Prime[k]*(Prime[k]-1)), {k, 1, n}]]]], {n, 2, 100}]

CROSSREFS

Cf. A091568, A091567, A005596, A048296.

Sequence in context: A155737 A140761 A100572 * A306190 A033622 A091568

Adjacent sequences:  A119531 A119532 A119533 * A119535 A119536 A119537

KEYWORD

frac,nonn

AUTHOR

Alexander Adamchuk, Jul 27 2006

STATUS

approved

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Last modified August 26 05:23 EDT 2019. Contains 326328 sequences. (Running on oeis4.)