## #22005 closed defect (fixed)

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

Reported by: | Sébastien Labbé | Owned by: | |
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Priority: | major | Milestone: | sage-7.6 |

Component: | symbolics | Keywords: | maxima |

Cc: | Merged in: | ||

Authors: | Reviewers: | ||

Report Upstream: | Fixed upstream, in a later stable release. | Work issues: | |

Branch: | Commit: | ||

Dependencies: | #18920 | Stopgaps: |

### Description (last modified by )

From ask.sagemath.org:

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.

### Change History (8)

### comment:1 Changed 6 years ago by

Description: | modified (diff) |
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### comment:2 Changed 6 years ago by

Description: | modified (diff) |
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### comment:3 Changed 6 years ago by

Report Upstream: | N/A → Fixed upstream, in a later stable release. |
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### comment:4 Changed 6 years ago by

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

### comment:5 Changed 5 years ago by

Status: | new → needs_review |
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### comment:6 Changed 5 years ago by

Status: | needs_review → positive_review |
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This is fixed in 8.0.beta11.

### comment:7 Changed 5 years ago by

Resolution: | → fixed |
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Status: | positive_review → closed |

### comment:8 Changed 5 years ago by

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

https://github.com/sagemath/sage/blob/develop/src/sage/calculus/calculus.py#L569

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

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Seems to be fixed upstream or "

perhaps an interaction with some flags that Sage is setting" according to Robert Dodier:https://sourceforge.net/p/maxima/bugs/3236/#7b13/aab3