Your objective is to write a program that takes an input, and, when chained together
N times, performs "sequential multiplication". What is sequential multiplication, you may ask? It's a sequence with a seed
a defined as thus:
f(0) = a f(n+1) = f(n)*(f(n)-1)
a = 5. Thus,
f(0) = 5,
f(1) = f(0)*(f(0)-1) = 5*4 = 20, and
f(2) = f(1)*(f(1)-1) = 20*19 = 380.
If your program was
ABC should take input
a and output
ABCABC should output
f(2), etc. Your program series should only take input once and only output once.
This is a code-golf so the shortest program in bytes wins. Standard loopholes are banned.