\\ A065361 Rebase n from 3 to 2. Replace 3^k with 2^k in ternary expansion of n. A065361(n) = fromdigits(digits(n, 3), 2) { nb = vector(2^9); \\ 0 based for (k = 0, 3^valuation(#nb, 2), v = A065361(k); if (1+v <= #nb, nb[1+v]++; ); ); vv = vector(#nb, k, vector(nb[k])); ii = vector(#nb); for (k = 0, 3^valuation(#nb, 2), v = A065361(k); if (1+v <= #nb, vv[1+v][ii[1+v]++] = k; ); ); m = -1; for (n=1, #vv, apply (v -> print (m++ " " v), vv[n]); ); } quit