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

Offset: 1

Author

Wolfdieter Lang, Jun 21 2011

Keywords

• nonn
• easy
• frac

Comments

See A191998.

Examples

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

Crossrefs

Cf. A191998, A191996/A191997.

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).