17 lines
694 B
Python
17 lines
694 B
Python
def catalan_number(num):
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if num <=1:
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return 1
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res_num = 0
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for i in range(num):
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res_num += catalan_number(i) * catalan_number(num-i-1)
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return res_num
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for n in range(10):
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print(catalan_number(n))
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# In combinatorial mathematics, the Catalan numbers form a sequence of natural numbers that occur in various counting problems, often involving recursively-defined objects. They are named after the Belgian mathematician Eugène Charles Catalan (1814–1894).
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Catalan number
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The first Catalan numbers for n = 0, 1, 2, 3, … are
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1, 1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796, 58786, 208012, 742900, 2674440, .... |