How can i use for loop instead of this?

clear all

clc

x= 1;

n=-1;

b=x;

a=1;

i=1

term(1,i)=(a^1)*n/factorial(1)

i=2

term(1,i)=(a^1)*(b^(1))*(n*(n-1))/factorial(2)

i=3

term(1,i)=(a^1)*(b^(2))*(n*(n-1)*(n-2))/factorial(3)

i=4

term(1,i)=(a^1)*(b^(3))*(n*(n-1)*(n-2)*(n-3))/factorial(4)

i=5

term(1,i)=(a^1)*(b^4)*(n*(n-1)*(n-2)*(n-3)*(n-4))/factorial(5)

Answer 1

[David Hill]

No loop needed. n*(n-1)*(n-2).../factorial() is just -1 or 1 alternating, placed -1 with x raised to power to alternate this sign.

term=a*(-x).^(0:4);