[重点]主攻273816头,主攻493816尾.
1,排除490头,162百,278十,尾270.
2,铁卒:34,35,84,89.
3,三字现:134,139,184,189,634,639,684,689.
4,二定:X3X4,X3X9.X8X4,X8X9,X31X,X36X,X81X,X86X,6XX9.
5,三定:13X4,13X9,18X4,18X9,63X4,63X9,68X4,68X9,6X19,6X69.
6,直码:6314,6319,6364,6369,6814.6819,6864,6869,1364,1369.