MathDB
2020 Team 8

Source:

February 2, 2020
team2020

Problem Statement

Simplify (20201010)(10101010)+(20191010)(10111010)++(10111010)(20191010)+(10101010)(20201010).\dbinom{2020}{1010}\dbinom{1010}{1010}+\dbinom{2019}{1010}\dbinom{1011}{1010}+\cdots+\dbinom{1011}{1010}\dbinom{2019}{1010} + \dbinom{1010}{1010}\dbinom{2020}{1010}.