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3 votes
2 answers
222 views

Can Mathematica simplify an ordinary differential equation (ODE) by assuming a power series solution and obtain the recurrence relation?

I have an ordinary differential equation and want to solve it using power series as ψ[x_] = Sum[Subscript[a, n] x^n, {n, 0, ∞}] to obtain the recurrence relation ...
PhysFan's user avatar
  • 63
4 votes
1 answer
170 views

How can I compute the $n$-th complete Bell polynomial?

I'm interested in computing the n-th complete Bell polynomial $ B_n(x_1,..., x_n) $ using the formula given as the last equation in the "Exponential Bell polynomials" section here (I tried ...
Robert Lee's user avatar
3 votes
2 answers
159 views

Recursive function with subscript

I am trying to define a recursive function with a subscript. Something similar would be $f_{n+1}(x) = \int 3 x f_{n}(x)dx$. I've tried lists, For function, ...
Vicente Sepúlveda Trivelli's user avatar
3 votes
3 answers
132 views

How to test a recursive formula using Mathematica?

Through taking the derivative of $\binom{n}{k}$ w.r.t $n$ repeatedly, I found the recursive formula: $$\frac{\partial^a}{\partial n^a}\binom{n}{k}=\sum_{j=0}^{a-1}\binom{a-1}{i}\frac{\partial^j}{\...
Ali Shadhar's user avatar
2 votes
2 answers
229 views

Why both DSolve and NDSolve are unable to solve a second-order differential equation?

I am trying to solve a recurrence relation using generating functions method: $$a_n=a_{n-1}+(n-1)a_{n-2}+(0.5n^2-1.5n+1)a_{n-3}$$ After some long calculations, I have arrived to this second-order ...
mikemykhaylov's user avatar
0 votes
1 answer
62 views

Help with recurrence relation

I try to solve the following recursion for $n \in \mathbb{N}$. $r_i = r_{i-1} - \frac{1}{2} \cdot \sqrt{1 - \frac{4\pi^2\cdot r_{i-1}^2}{n^2} \cdot \cos^2 \left(\frac{\pi}{n}\right)}$ $r_0 = \...
Jannik's user avatar
  • 257
1 vote
1 answer
97 views

Recurrences with some relation to Dedekind eta functions

Dedekind eta functions are know to satisfy certain difference equations/recurrence relations. The same is true for ratios of eta functions. Suppose some ratio of eta functions, say $A(q)$ satisfies ...
Leucippus's user avatar
  • 365
3 votes
2 answers
572 views

How can I calculate the volume of a Sphere in $R^n$? [duplicate]

The radius of the sphere is the set of the Points $\{x\mid r^2=|x|^2\}$, where the sphere is in $R^n$. We describe the volume as $V_n(r)$, How can I prove the characteristic of the sphere, that: $$...
Jone Will's user avatar
-1 votes
2 answers
178 views

Finding the limit of a nonlinear recursion sequence as $n$ goes to ∞

I want to find the limit as n goes to infinity of the nonlinear recursion sequence ...
Fatalist's user avatar
4 votes
1 answer
164 views

Strategies for simplifying recurrences with sums

The problem: Count the number of permutations of n distinct objects that leave none of them fixed. This is actually a well-studied problem with pretty well-...
Exp HP's user avatar
  • 143
7 votes
5 answers
2k views

Limit n->Infinity of recursive sequence

I have defined a recursive sequence a[0] := 1 a[n_] := Sqrt[3] + 1/2 a[n - 1] because I want to calculate the Limit for this ...
Azure's user avatar
  • 173
7 votes
2 answers
935 views

Integrating a periodic function

I have a periodic function ff: ff := Function[x, Piecewise[{{ff[x - 1], x >= 1}, {2 x, 0 <= x < 1}, {ff[x + 1], x < 0}}]] Plotting it works fine: <...
Patrik's user avatar
  • 71
0 votes
1 answer
277 views

Explicit, closed formula for recursive integral as a function of the recursive parameter

This is a follow-up of this question/answer. I'm working on a recursive integral more complicated than the one on the linked question, but this one can be used as an example. I would like to obtain ...
drake's user avatar
  • 101
11 votes
2 answers
940 views

Recursive Integral for Volume of $n$-Ball

The volume of an $n$-ball (the $(n+1)$-dimensional analogue of a disk) of radius $r$ can be found by the following integral recurrence: $$V_0(r)=2r$$ $$V_n(r)=\int_{-r}^rV_{n-1}\left(\sqrt{r^2-x^2}\...
David Zhang's user avatar
  • 2,336
6 votes
3 answers
2k views

recursive integration

I am trying to do multiple integrations recursively. For instance, I would like to do the following equation for arbitrary integer $n$: $\displaystyle R_n(t) = \int_0^t \mathrm dt' R_0(t-t') R_{n-1}(...
BeauGeste's user avatar
  • 2,877