A191999 - OEIS

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A191999

Denominators of partial products of a Hardy-Littlewood constant.

1, 2, 8, 16, 160, 640, 2048, 12288, 24576, 32768, 327680, 786432, 10485760, 62914560, 125829120, 167772160, 9730785280, 583847116800, 3503082700800, 245215789056000

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

See A191998.

LINKS

Table of n, a(n) for n=1..20.

FORMULA

a(n) = denominator(r(n)) with

r(n):=product(1-Chi_2(4;p(j))/(p(j)-1),j=1..n), n>=1, with the primes p(j)=A000040(j) and the nontrivial Dirichlet Character modulo 4, called here Chi_2(4;k) = A056594(k).

EXAMPLE

The rationals r(n) are: 1, 3/2, 9/8, 21/16, 231/160, 847/640, 2541/2048, ...

CROSSREFS

Cf. A191998, A191996/A191997.

Sequence in context: A013516 A259688 A101059 * A101658 A308613 A006573

Adjacent sequences: A191996 A191997 A191998 * A192000 A192001 A192002

KEYWORD

nonn,easy,frac

AUTHOR

Wolfdieter Lang, Jun 21 2011

STATUS

approved