O(n) and time complexity function of the given code

  analysis, big-o, c++, time-complexity

if the following loop structure is under Analysis of Upper bound. Does it still Computes to O(n^2)?
I’m confused since inner loop has a dependency on the outer loop and with each outer iteration inner for loop loops one less time.
In addition to whatever O(n) is does the time complexity function will be "n!.n+C" Where C is a Constant? I’m assuming n! because of inner Loop.

for(int i=n;i>0;i--)
 for(int j=i;j>=1;j--)

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