2,24,720, 40320, 3628800 Write an expression for the n'th term of the sequence. (There is more than one correct answer.)

2,24,720,40320,3628800
Let's write the series as,
2*1,4*3*2*1,6*5*4*3*2*1,8*7*6*5*4*3*2*1,10*9*8*7*6*5*4*3*2*1
From the above pattern we can write the series as,
2!,4!,6!,8!,10!
So based on the above pattern, we can write the n'th term of the series as:
a_n=(2n)!