Opened 6 years ago

Closed 6 years ago

# sum(1/((2*n+1)^2-4)^2, n, 0, oo, algorithm='maxima') is wrong

Reported by: Owned by: slabbe major sage-7.6 symbolics maxima Fixed upstream, in a later stable release. #18920

```sage: n = var('n')
sage: sum(1/((2*n+1)^2-4)^2, n, 0, oo)
1/64*pi^2 - 1/12
sage: sum(1/((2*n+1)^2-4)^2, n, 0, oo, algorithm='maxima')
1/64*pi^2 - 1/12
```

but correct answer is `1/64*pi^2`. SymPy (with #22004) and Mathematica do it right:

```sage: sum(1/((2*n+1)^2-4)^2, n, 0, oo, algorithm='mathematica')
1/64*pi^2
sage: sum(1/((2*n+1)^2-4)^2, n, 0, oo, algorithm='sympy')
1/64*pi^2
```

I am using version:

```\$ sage -standard | grep maxima
maxima..................................5.35.1.p2 (5.35.1.p2)
```

See #18920 for the ticket updating maxima version.

### comment:1 Changed 6 years ago by slabbe

Description: modified (diff)

### comment:2 Changed 6 years ago by slabbe

Description: modified (diff)

### comment:3 Changed 6 years ago by slabbe

Report Upstream: N/A → Fixed upstream, in a later stable release.

Seems to be fixed upstream or "perhaps an interaction with some flags that Sage is setting" according to Robert Dodier:

### comment:4 Changed 6 years ago by dimpase

Dependencies: → #18920 sage-7.5 → sage-7.6

this is to be fixed in #18920; this bug does not appear in the currently tested configuration of ECL-16.1.3+Maxima 5.39.0; this ticket should be closed after #18920 is done.

### comment:5 Changed 6 years ago by slabbe

Status: new → needs_review

### comment:6 Changed 6 years ago by slabbe

Status: needs_review → positive_review

This is fixed in 8.0.beta11.

### comment:7 Changed 6 years ago by vbraun

Resolution: → fixed positive_review → closed

### comment:8 Changed 6 years ago by slabbe

Just to say that a doctest is already testing this issue:

It was added in #22004 and updated during the upgrade to maxima 5.39.

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