(47,55) d=8 cells=2502 symmetric SAT in 24s, check: ok, R=15 (I/3=15)
(46,56) d=10 cells=2475 symmetric SAT in 10s, check: ok, R=33 (I/3=33)
(45,54) d=9 cells=2340 symmetric SAT in 15s, check: ok, R=24 (I/3=24)
(51,60) d=9 cells=2964 symmetric SAT in 61s, check: ok, R=22 (I/3=22)
