s = 0 unseen = 0 seen(v) = bit test(s, v) see(v) = s = bit or(s, 2^v); while (seen(unseen), unseen++) p = 0 other() = { for (v=unseen, oo, if (!seen(v), my (pv=bitxor(p,v)); if (issquare(pv), p=pv; see(v); return (v); ); ); ); } for (n=0, 2^13, print (n " " other())) quit