Mathematical problem-the problem of planting 20 trees in the same century There is a problem of planting 20 trees in the history of mathematics, which has been famous all over the world for centuries and constantly nourishes and inspires human wisdom. With the centuries of human civilization, it has been decorated in the flowers of high-end arts and crafts. Its beauty is enduring, increasing, progressing and developing, and it is more fragrant, exquisite and colorful in the process of human civilization. As early as16th century, ancient Greece, ancient Rome, ancient Egypt, etc. Sixteen rows have been arranged, and beautiful maps have been widely used in elegant decorative buildings and gorgeous arts and crafts (Figure 1). /kloc-In the 8th century, the German mathematician Gauss guessed that the problem of planting 20 trees should reach the 18th line, but he never published the 18th line map. It was not until19th century that this conjecture was completed by Sam Lloyd, an American master of entertainment mathematics, and an exquisite eighteen-line atlas was drawn. Later, it was made into entertainment chess, which prevailed in Europe and America and was deeply loved by people (Figure 2). & lt& gt