Some properties of leetcode139 Yang Hui triangle

Yang Hui triangle has special properties

1. Each line of numbers is symmetrical from 1 Start getting bigger and smaller , And finally back to 1.
2. $$The\; firstnThat\text{'}s\; ok(from0openbeginningEdNumber)CountwordYesn+1term,frontnThat\text{'}s\; okcommonYes\frac{n(n+1)}{2}individualCount$$
3. $$The\; firstnThat\text{'}s\; okOfThe\; firstmindividualCount（from0openbeginningEdNumber）cansurfaceinbyGroupcloseCount{\mathrm{C}}_n^m=\frac{n!}{m!(n-m)!}$$
4. Each number is equal to the sum of the left and right numbers in the previous line
5. $$(a+b{)}^{n}Ofexhibitionopentype（Twotermtypeexhibitionopen）inOfvarioustermsystemCountIn\; accordance\; with\; theTimeYesShould\; beYangBrightness3、\; ...\; andhornThe\; firstnThat\text{'}s\; okinOfEvery\; timeOneterm(Such\; as：(a+b{)}^2=a^2+2ab+b^2)$$