45141 is a symmetrical 3 object siteswap. This pattern is essentially 441 with one round of a shower (51) between the two 4s.
To learn it, you need to be comfortable with 441 and 51, and going smoothly between those two patterns. It also helps to be able to do 41401 and 12345.
Variations[]
You can do any number of showers before going back to 441, to get tricks like 4515141, 451515141, etc.
56252 is a 4 ball equivalent.
Beat old records - 3 ball 45141
3 ball 45141 by Ilia Poliakov