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Double sum

asked 2012-11-26 08:41:27 -0500

PB gravatar image

Hello,

I would like SAGE to compute a double sum like $\sum\limits_{1\le a\le n}\sum\limits_{1\le b\le n} \max(a,b)$. The result is strange :

f(n)=sum(sum(max(a,b),b,1,n),a,1,n)

SAGE tells me that f(2) is 6. But it is rather 7 (unless i am very tired).

Thank you for your advices :-)

Pierre

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answered 2012-11-26 09:48:26 -0500

PB gravatar image

Thank you. You are right : max(a,b) gives me a. I used max_symbolic instead, I get no error, but SAGE can't simplify the double sum.

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answered 2012-11-26 09:29:34 -0500

kcrisman gravatar image

In this case you may want to try max_symbolic. Try max(a,b) by itself and see what you get - maybe a?

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Asked: 2012-11-26 08:41:27 -0500

Seen: 448 times

Last updated: Nov 26 '12