# Finding n in equivalence between two permutations

Find the value(s) of n: 2P(n, 2)+50 = P(2n, 2)

For 2P(n, 2)+50 I simplified to 2(n)(n-1)+50. For P(2n, 2) I can't get any simpler than $2n\times(2n-1)\times...\times(n+1)\times n\times(n-1)$ and I'm stuck.

BTW what's the LaTex for pick notation?