'Corners only' U (17)
2R2 u2 2R2 u 2R2 u2 2R2 u' 2R2 u 2R2 u' 2R2 u2 2R2 u' 2R2

F/B 3 centre swap (25)
2R u2 2R2 u2 2R' u 2R2 u' 2R2 u 2R' u 2R2 u 2R2 u2 2R2 u' 2R2 u 2R2 u2 2R2 u 2R'

UF edge flip (27)
2R2 u2 2R' u 2R u2 2R u 2R u 2R u' 2R' u' 2R u 2R u 2R' u2 2R2 u2 2R' u' 2R u2 2R2

UF/UL edge swap (29)
2R u 2R' u' 2R u2 2R2 u' 2R' u2 2R u' 2R' u 2R2 u' 2R u 2R' u2 2R u 2R2 u2 2R' u 2R u' 2R'

F/B 3 centre swap + L/R 2 centre swap (31)
2R u 2R2 u 2R u2 2R2 u2 2R2 u' 2R2 u2 2R2 u 2R u' 2R2 u 2R2 u' 2R' u' 2R2 u' 2R2 u 2R u' 2R2 u' 2R


Centres distribution: Depth New Total 0 1 1 1 6 7 2 18 25 3 54 79 4 162 241 5 482 723 6 1423 2146 7 4174 6320 8 12292 18612 9 36146 54758 10 106425 161183 11 313009 474192 12 919206 1393398 13 2695438 4088836 14 7880825 11969661 15 22883836 34853497 16 65423943 100277440 17 179899126 280176566 18 449508902 729685468 19 888449527 1618134995 20 1020467510 2638602505 21 373535425 3012137930 22 14880451 3027018381 23 5619 3027024000 24 0 3027024000