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The fourth central triangular number, the third central hexagonal number, the index of the seventh mersenne prime of the third octahedral number and the previous 17 form a set of twin prime cycle units11111. 38+0111is the reciprocal of prime number119 = 0.052631578947368421

In music

"19" is a top single of pop music charts, which was written and released by Paul Hardcastle in 1985. This electronic single with a lot of anti-war consciousness in the lyrics got its name because according to statistics, the average age of American officers and men who went to the battlefield during the Vietnam War was exactly 19 years old.

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Atomic number of potassium

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In general Weiqi matches, 19 chessboard is used as the network language of student number under certain circumstances.

19 The capital of China is 19th. The pinyin of "Nineteen" begins with "SJ" and can be spelled as "nerve". So, 19 means nerve.