What is Earlier Heaven Sequence?

The trigram arrangement attributed to Fu Xi, representing the primordial cosmic order. Trigrams are arranged in complementary pairs: ☰ Qian–☷ Kun, ☳ Zhen–☴ Xun, ☵ Kan–☲ Li, ☶ Gen–☱ Dui. This sequence forms the basis of Shao Yong's cosmological numerology and the Plum Blossom numerology system. It differs from the Later Heaven sequence used in feng shui and directional applications.

Source: Shuogua Zhuan (說卦傳); Huangji Jingshi Shu (皇極經世書), Shao Yong