move(z) = {
	my (w=max(abs(real(z)), abs(imag(z))));
	if (imag(z)==-w, z+1,
		real(z)==-w, z-I,
		imag(z)==+w, z-1,
	                 z+I);
}

T = matrix(1+2*M=51, 1+2*M);
get(z) = T[1+M+real(z), 1+M+imag(z)]
set(z, v) = T[1+M+real(z), 1+M+imag(z)] = v

{
	z=0;
	for (n=1, (1+2*M)^2,
		set(z, n);
		z = move(z);
	);

	dz = powers(I,3);
	dz = concat(dz, dz*(1+I));

	z=0;
	for (n=1, 2*M^2,
		print (n " " vecsum(apply(d -> get(z+d), dz)));
		
		z = move(z);
	);
}

quit