3 Jul
2013
3 Jul
'13
9:13 p.m.
Prove sum_(j = 0)^(j = n) (2j)_C_j (2n-2j)_C_(n-j) = 4^n eg. with n = 4 , 1.20 + 2.6 + 6.2 + 20.1 = 64 Fred Lunnon