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Unformatted text preview: (c) Let w n be the number of webs with vertex set n . Write down a recursion for w n and explain how you got it. (d) Prove that, for n ≥ 3 the number of webs with vertex set n is ( n1)! ( n2)! 2 n2 . Here are some values of b n and binomial coeﬃcients. b 1 = 1 b 2 = 1 b 3 = 2 b 4 = 5 b 5 = 14 b 6 = 42 . ± 6 4 ¶ = 15 ± 7 4 ¶ = 35 ± 8 4 ¶ = 91 ± 5 3 ¶ = 10 ± 6 3 ¶ = 20 ± 7 3 ¶ = 35 ± 8 3 ¶ = 56 ± 4 2 ¶ = 6 ± 5 2 ¶ = 10 ± 6 2 ¶ = 15 ± 7 2 ¶ = 21 ± 8 2 ¶ = 28 ± 9 2 ¶ = 36 ± 10 2 ¶ = 45...
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This note was uploaded on 06/18/2009 for the course MATH 184a taught by Professor Staff during the Fall '08 term at UCSD.
 Fall '08
 staff
 Math

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