Re: Help: How to calculate quickly this sum 192,255,317....1218,1262?
- From: Kiuhnm <"kiuhnm03["@]yahoo.it>
- Date: Sat, 25 Feb 2006 13:30:14 +0100
gnh888@xxxxxxxxx ha scritto:
Any chance to explain how you calculate the sum?
The polynomial is
p(x) = 128 + 129x/2 - x^2/2.
If S = Sum_{x=1}^n then
S p(x) = 128 S 1 + 129/2 S x - 1/2 S x^2
S 1 = n,
S x = n(n+1)/2,
S x^2 = n/6+n^2/2+n^3/3
then
S p(x) = 961n/6+32n^2-n^3/6
Kiuhnm
.
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- Help: How to calculate quickly this sum 192,255,317....1218,1262?
- From: gnh888@xxxxxxxxx
- Re: Help: How to calculate quickly this sum 192,255,317....1218,1262?
- From: Kiuhnm
- Re: Help: How to calculate quickly this sum 192,255,317....1218,1262?
- From: gnh888@xxxxxxxxx
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