{ for (n = 1, #a = vector(10 000), x = 2^0; for (w = 1, oo, if (n-2*w < 1, break, [u, v] = vecsort([a[n-2*w], a[n-w]]); d = v-u; \\ u v c c = v+d; x = bitor(x, 2^c); \\ c u v c = u-d; if (c > 0, x = bitor(x, 2^c); ); \\ u c v c = (u+v)/2; if (type(c)==type(42), x = bitor(x, 2^c); ); ); ); print (n " " a[n] = valuation(x+1, 2)); ); } quit