golang 正则匹配报错

请问这个是什么原因如何修改?

var reg_pattern = regexp.MustCompile("^(<a>\\d)(\\d)(\\d)\\1\\2\\3$")
    if reg_pattern.MatchString(convert.IntToStr(uid)) {
            return true
        }
panic: regexp: Compile(`^(<a>\d)(\d)(\d)\1\2\3$`): error parsing regexp: invalid escape sequence: `\1`

还有这个是什么原因 如何修改?

var reg_pattern13 = regexp.MustCompile("(?:(?:0(?=1)|1(?=2)|2(?=3)|3(?=4)|4(?=5)|5(?=6)|6(?=7)|7(?=8)|8(?=9)|9(?=0)){2,}|(?:0(?=9)|9(?=8)|8(?=7)|7(?=6)|6(?=5)|5(?=4)|4(?=3)|3(?=2)|2(?=1)|1(?=0)){2,})\\d")
        if reg_pattern13.MatchString(convert.IntToStr(uid)) {
            return true
        }
panic: regexp: Compile(`(?:(?:0(?=1)|1(?=2)|2(?=3)|3(?=4)|4(?=5)|5(?=6)|6(?=7)|7(?=8)|8(?=9)|9(?=0)){2,}|(?:0(?=9)|9(?=8)|8(?=7)|7(?=6)|6(?=5)|5(?=4)|4(?=3)|3(?=2)|2(?=1)|1(?=0)){2,})\d`): error parsing regexp: invalid or unsupported Perl syntax: `(?=`