The SP-404MK2 lets you record patterns using time signatures from 1/4 to 7/4. On the pattern settings screen, turn the [CTRL 2] knob while holding down the [SHIFT] button to select a time signature.
For details, refer to “Creating a new pattern (real-time recording)” and “Creating a new pattern (TR-REC)” in the SP-404MKⅡ Reference Manual.