construct/mc hadamard
construct/mc hadamard: a task in MathConstructOptimize-Envs-harbor (Harbor dataset). Find two sequences x 0..20 and y 0..20 with entries in {-1, +1} (a Legendre pair of length 21) such that (a) sum(x) = 1 and sum(y) = 1, and (b) for every k = 1..10: sum {i=0}^{20} x i x (i+k) mod 21 + sum…
The task
Find two sequences x[0..20] and y[0..20] with entries in {-1, +1} (a Legendre pair of length 21) such that (a) sum(x) = 1 and sum(y) = 1, and (b) for every k = 1..10: sum_{i=0}^{20} x[i]*x[(i+k) mod 21] + sum_{i=0}^{20} y[i]*y[(i+k) mod 21] = -2.