Inspired by this

• 1
• 1(2*)(3*)(4*)
• (1+2+)|(3+4+)
• .*(31|13)(.*)
• (4[^4]{2}2+)
• ([13][24]|[24][13]){4}$
• ((?:(.)\2+)+)
• ((?:31|13|24|42)+)()(.*)
• (?=((?:13|31)*))(?=((?:24|42)*))(?=([13]*[24]*))