When the body of Dr. Mark Sloan's long-missing father was discovered in a Los Angeles tomb, his detective's badge had been placed inside the crypt as well. Back in 1947 (when he was last seen alive), Detective James Sloan held badge number "416".
This was all seen in the 'Diagnosis Murder' episode "Sins Of The Father Part Two".
"4" and "16" are two of the Numbers in the sequence from 'Lost'.....
[With the frame grab, it does sort of look like "418", but Dr. Sloan's son did say it was "416".]