**Vector summation:**

‘’’ sum([1/n^2 for n = 1:100000])’’’

returns: 1.644924066898228

**Generator summation:**

‘’‘sum((1/n^2 for n = 1:100000))’’’

returns: 1.6449240668982423

Why is there a difference in these results, and which summation method is the most accurate?

https://0.30000000000000004.com/. The list version uses pairwise summation which means on average it will be slightly more accurate.

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Thank you. For clarification, is the list version the vector summation method (i.e. enclosed in with brackets)?

Per
#5
For an even more accurate result, sum the terms in order of increasing absolute value:

```
sum((1/n^2 for n = 100000:-1:1)) # returns 1.6449240668982263
```

or use BigFloat:

```
sum((1/big(n)^2 for n = 1:100000)) # returns 1.64492406689822626980574850331269185564752...
```

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