tr(v)=if (v>=0, 1+2*v, -2*v)
ss = 0
seen(v) = my (w=tr(v)); bittest(ss,w)
see(v) = my (w=tr(v)); ss=bitor(ss,2^w)

allocate mem(2^30)

s = [0]
z = 0

{
	for (n=1, oo,
		t=digits(n,2);
		for (k=1, #t,
			if (t[k],
					z++;
					if (#s<z, s=concat(s,vector(#s)));
					s[z] = t[k],
					z--;
					s[z] = -(s[z+1]-s[z])
			);
		);
		if (!seen(s[z]),
			print (m++ " " s[z]);
			if (m==10 000, break);
			see(s[z]);
		);
	);
}

quit