Changing Step 4 in this sequence results in A117154 (see link). Plotting against A125141 returns an "elliptic spiral". As music (example settings): Compute pitch by scaling: 11-66, perform division operation. Compute duration by scaling: 0-2, perform division operation

This sequence is calculated by noting the coefficient of the unit basis vector of the floretion Y after each iteration (see link for further details). Note: this basis vector may also be represented as the unit 4 X 4 matrix.