how to write the code code for this operation right?

how to write the code of the term on the right?

[Rik]

Why did you edit away your question? That is very rude.

To save other editors time: this question is not in the Google cache, nor in that of Bing or Yahoo.

[Fulbert Nguepi]

Sorry it was a mistake

[Walter Roberson]

Easy way to fix the mistake: post the question text again.

Answer 1

[Walter Roberson]

syms alpha h n u(x,t)
Pi = sym(pi);
part1 = u(x-n*h,t) + u(x+n*h,t)

part1 = 

part2 = (-1)^n * gamma(alpha+1) / gamma(n+1) / gamma(alpha-n+1)

part2 = 

part3 = symsum(part1 * part2, n, 0, inf)

part3 = 

right_side = 1/(2*cos(Pi*alpha/2)) / h^alpha * part3

right_side =