# Questions tagged [summation]

Questions using the Sum command, especially for series and other algebraic objects, and related functions such as SumConvergence

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### Stop Mathematica from rounding the value

My task is simple. Calculate the average value for 10^7 dice throws using computer pseudo-random-number-generator. x := RandomInteger[{1, 6}] gives me one ...
109 views

### Long time to solve numerical integration involved summation over large n

I need to solve this numerical integration to plot w as a function of x.. ...
432 views

### The simplest way to sum the elements of a n*1 -matrix [closed]

Suppose we have a 10*1 (n*m) matrix: b = {{2}, {3}, {4}, {5}, {6}, {7}, {8}, {9}, {10}, {11}} // MatrixForm Now, if I want to sum the elements of this matrix ...
411 views

### Plot a summation

How can I plot f = Sum[(4 Sqrt)/(n^2 π^2) Sin[(n π)/2], {n, 1, 20}] I need to plot the sum of the first 20 terms.
305 views

### Relabeling of dummy variables

I have the following expression F[p1, p2] a[p1] ** b[p2] - F[p1, p2] a[p2] ** b[p1] where ** is the non-commutative ...
60 views

### Why MMA cannot get the closed-form of this infinite series of B when it known that of A+B and A?

The following input s1 = Sum[(2 l + 1)*t^l*LegendreP[l, Cos[θ]], {l, 0, Infinity}, Assumptions -> {t < 1, 0 < θ < π}] returns the closed-form ...
650 views

### Possible bug in infinite sum Sum[(Sin[k]/k)^m,{k,0,∞}]

EDIT 11.10.2017 In order to avoid confusion which might arise from the statements I made in this question I declare here that the extensive discussion here has shown that the described behaviour is ...
63 views

### Leave Kronecker deltas unevaluated

When performing sums over Kronecker deltas, how can I tell Mathematica to leave deltas that are not summed over unevaluated? In particular, the following expression contains indices $i$, $j$, $k$, $l$....
75 views

### Why my code for format change doesn't work? (Format Rules)

I want to write the following in mathematica $$(\sum_{k=1}^n a^2_k)$$ Now I've written this as an indexed variable Sum[(a^2)[k], {k, 1, n}] which in ...
476 views

### Summation bug in 11.2

If I sum all the positive-numbered Fourier coefficients of $\cos(x)$, I get the correct answer. If I sum the negative-numbered ones, I get a wrong answer. Splitting the sum into two parts somehow ...
130 views

Is it a bug? ...
50 views

### Help to implement an expression

How can I implement this summation in Mathematica, where $r$, $k$ and $n$ are fixed value: r=3; k=0; n=0; Edit: Is that right? ...
101 views

321 views

### Contracting Levi-Civita [duplicate]

I am trying to contract two Levi-Civita symbols in tensor format like so: $\epsilon_{a b} \epsilon_{c d}$ This code generates the Levi-Civita: ...
90 views

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### Summing over Prime Factors (without repetition)

Wolfram Mathworld (http://mathworld.wolfram.com/SumofPrimeFactors.html) describes a function sopfr(n), the sum of prime factors, which I currently need. This code doesn't work when I insert it in ...
145 views

### Does this sum converge?

If I input: Sum[Binomial[-1/2, n], {n, 0, ∞}] MMA returns: Sum::div: Sum does not converge. >> But I think that this sum does converge. It is an alternating ...
122 views

### How can show my series converges to zero [closed]

I have a summation, with that goes for 1 to ∞. I suspect that it should converge to zero as n -> ∞. ...
581 views

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

I have a 150 by 300 binary matrix. I would like to sum the 1's for each individual row (from left to right) until the first zero is encountered. For example, if a given row is 1 1 1 1 1 1 0 0 0 1 0 0 ...
48 views

### Numerical result using summation limit

I'm exploring the possibilities of the Limit function: Example 1: $\lim_{x\to \infty } \, \frac{\sqrt{x-1}}{x}$ ...
105 views

### Code for specific sum

Given a positive integer $n$, let $p$ denote the largest prime $p$ less than $2^n$. That is, $p$ equals Max[Table[Prime[i], {i, 1, PrimePi[2^n]}]] I want to ...
91 views

### Hecke Operator- sum over divisors of a number

I am trying to write out the Hecke Operator; however, I don't know how to sum over all divisors of an integer. Could someone please give me some advice how to do that. Below is the Hecke Operator ...
146 views

### Having problem with using Replace in Do-loop

I am trying to set to zero some expression in a very long summation in mathematica. So I have decided to use a do loop along with a the replace operator over all indices I want to remove (actually ...
141 views

### Sum indexed by Primes [duplicate]

How can I express a sum indexed by primes in Mathematica? Two examples that I am interested in are (1) where the primes go from $p=2$ to, say, $p=17$. (2) It would also be useful to have the sum ...
65 views

### Not able to plot a function of two variables defined by summation

I have the following code: ...