A120832 Denominators of partial sums of (p+q)/p*q, where p and q are primes.

1, 6, 2, 5, 70, 210, 210, 1155, 1155, 30030, 10010, 85085, 17017, 646646, 1939938, 22309287, 22309287, 22309287, 111546435, 37182145, 2156564410, 33426748355, 33426748355, 100280245065, 7420738134810, 7420738134810

Offset

1,2

Comments

Numerators: A120831(n);

A120831(n)/a(n) = Sum(A068318(n)/A001358(n):1<=k<=n).

Links

Table of n, a(n) for n=1..26.

Example

n=5: (2+2)/2*2+(2+3)/2*3+(3+3)/3*3+(2+5)/2*5+(2+7)/2*7 =
4/4 + 5/6 + 6/9 + 7/10 + 9/14 = 269/70 = A120831(5)/a(5).

Crossrefs

Cf. A120835, A120834.

Sequence in context: A220260 A238901 A166200 * A248271 A021988 A021619

Adjacent sequences: A120829 A120830 A120831 * A120833 A120834 A120835

Keyword

nonn,frac

Author

Reinhard Zumkeller, Jul 24 2006

Status

approved