# Tag Info

Accepted

### Why can't Mathematica compute the series $\sum_{n=1}^{\infty} \frac{\mu(n)}{e^{2n}-1}$?

you can try Sum[(MoebiusMu[k]*q^k)/(1 - q^k), {k, 1, Infinity}] /. q -> Exp[-2] (* 1/E^2 *)
• 3,437
Accepted

### How to derive a closed-form expression for the sum of this series?

Maple: s:=sum(x^(9 + 6*k)/(9 + 6*k)!, k=0..infinity) simplify(convert(s,trig)) Mathematica V 14: ...
• 146k

### Bugs with Sum?

Many times in Sum[], n = 0 seems to be a special case connected with bugs. Separate out ...
• 237k

### Recurrence relation with a sum

RecurrenceTable[ {t[n + 1] == 2 t[n] t[n - 1] + If[n > 1, t[n], 0], t[1] == 2, t[0] == 2}, t[n], {n, 6}] (* {2, 2, 8, 40, 680, 55080, 74963880} *)
• 237k

### Bugs with Sum?

I guess MMA first do the substitution $j\to n-k$, and then there is a bug of Sum for $n=0$ ...
• 2,423
Accepted

### Break summation of terms in summations of each term

Use Distribute, optionally with Expand. ...
• 27.1k
Accepted

...
• 160k
Accepted

### Double sum error message for NSum

Slow: NSum[1/((2 i + 1)^4 + (2 j + 1)^4), {i, -1000, 1000}, {j, -1000, 1000}, NSumTerms -> 10000] // RepeatedTiming (* {4.82287, 2.1729} *) Somewhat fast:...
• 3,277

### Recurrence relation with a sum

You can use Nest and BlockMap, e.g. ...
• 62k
Accepted

### How to use Sum properly to avoid problems when the summating limits are undefined?

When you give non-numeric limits, Sum will actually never see your P[x] = 1 definition, because it will evalute the general term ...
• 27.1k
Accepted

### Breaking multiple summations of terms in single term summations

Use a set of replacement rules implementing some simplification rules: ...
• 23.9k

One way ...
• 146k

### How to find the sum for each individual row in a binary matrix until the first zero is reached from left to right.

Just to participate: using: ...
• 62k

...
• 77.5k

### Mathematica incorrectly claims an infinite sum doesn't converge

Looks like Mathematica dosen't know how compute this series. Workaround: ...
• 14.2k
1 vote