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A146485 Decimal expansion of Product_{n=2...infinity} (1-1/(n^2*(n-1))). 0
6, 7, 3, 9, 1, 7, 3, 6, 3, 3, 7, 6, 3, 5, 7, 5, 4, 1, 6, 6, 4, 4, 0, 8, 9, 7, 9, 3, 2, 2, 6, 3, 4, 4, 3, 8, 5, 6, 4, 7, 5, 9, 8, 1, 2, 3, 1, 2, 6, 7, 1, 7, 3, 6, 7, 9, 2 (list; constant; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

Product of Artin's constant of rank 2 and the equivalent almost-prime products.

LINKS

R. J. Mathar, Hardy-Littlewood constants embedded into infinite products over all positive integers, arXiv:0903.2514 [math.NT], table 3, first line with r=2. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 28 2009]

FORMULA

The logarithm is -sum_{s>=2} sum_{j=1..floor[s/(1+r)]} binomial(s-r*j-1,j-1)*(1-Zeta(s))/j at r=2.

s*sum_{j=1..floor[s/3]} binomial(s-2j-1,j-1)/j = A001609(s)-1.

Equals 1/product_{k=1..3} Gamma(1-x_k), where x_k are the 3 roots of the polynomial x*(x+1)^2-1. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 20 2009]

EXAMPLE

0.6739173633763... = (1-1/4)*(1-1/18)*(1-1/48)*(1-1/100)*...

MAPLE

r := 2 : ni := fsolve( (n+1)^r*n-1, n, complex) : 1.0/mul(GAMMA(1-d), d=ni) ; [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 20 2009]

CROSSREFS

Cf. A065414.

Sequence in context: A139350 A092560 A018248 * A049254 A144028 A089321

Adjacent sequences:  A146482 A146483 A146484 * A146486 A146487 A146488

KEYWORD

nonn,cons

AUTHOR

R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 13 2009

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Last modified February 18 00:14 EST 2012. Contains 206085 sequences.