A057038 Let R(i,j) be the rectangle with antidiagonals 1; 2,3; 4,5,6; ...; each k is an R(i(k),j(k)) and A057038(n)=i(2n).

1, 1, 3, 2, 4, 2, 4, 1, 3, 5, 1, 3, 5, 7, 2, 4, 6, 8, 2, 4, 6, 8, 1, 3, 5, 7, 9, 1, 3, 5, 7, 9, 11, 2, 4, 6, 8, 10, 12, 2, 4, 6, 8, 10, 12, 1, 3, 5, 7, 9, 11, 13, 1, 3, 5, 7, 9, 11, 13, 15, 2, 4, 6, 8, 10, 12, 14, 16, 2, 4, 6, 8, 10, 12, 14, 16, 1, 3, 5, 7, 9