A(n, k) = fromdigits(binary(n), 3) + fromdigits(binary(k), 3) { print ("0 0"); a = vector(9841); u = 1; for (d = 1, 2^9-1, for (k = 0, d, v = A(d-k, k); if (!a[v], a[v] = m++; while (a[u], print (u " " a[u]); if (u++ > #a, break (3); ); ); ); ); ); } quit