A120834 Denominators of partial sums of (p+q)/p*q, where p and q are primes.

1, 5, 10, 70, 630, 2520, 2520, 32760, 32760, 32760, 32760, 622440, 622440, 622440, 1244880, 6224400, 6224400, 6224400, 1556100, 17117100, 530630100, 530630100, 176876700, 176876700, 176876700

Offset: 1

Author

Reinhard Zumkeller, Jul 24 2006

Keywords

• nonn
• frac

Comments

Numerators: A120833(n);

A120833(n)/a(n) = Sum(A001358(n)/A068318(n):1<=k<=n).

Examples

			n=5: 2*2/(2+2)+2*3/(2+3)+3*3/(3+3)+2*5/(2+5)+2*7/(2+7) =
4/4 + 6/5 + 9/6 + 10/7 + 14/9 = 4211/630 = A120833(5)/a(5).
		

Crossrefs

Cf. A120836, A120832.