" For any integer "n>=1,sum_(k=1)^(n)k(k+2)" is equal to "

For any integer n>=1, then sum_(k=1)^(n)k(k+2)=

For any integer n ge 1 , then sum_(k=1)^(n) k ( k+2) is equal to

The sum sum_(k=1)^(n)k(k^(2)+k+1) is equal to

sum_(k=1)^(3n)6nC_(2k-1)(-3)^(k) is equal to

If Delta_(k) = |(k,1,5),(k^(2),2n +1,2n +1),(k^(3),3n^(2),3n +1)|, " then " sum_(k=1)^(n) Delta_(k) is equal to