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A339787
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Number of homeomorphically irreducible leaf colored trees with n leaves using exactly 4 colors.
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2
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0, 0, 0, 4, 68, 812, 8512, 84312, 814184, 7781712, 74182124, 708344640, 6790655496, 65440865012, 634347822304, 6186652422650, 60707391493004, 599283097168488, 5950282272766412, 59408426130151164, 596269843123151304, 6014472189177940224, 60952019560703982452
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OFFSET
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1,4
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LINKS
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EXAMPLE
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There are 2 homeomorphically reduced trees with 4 leafs:
o o o
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o---o---o o---o
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o o o
The leaves of the first tree can be colored in 1 way using all four colors and the second can be colored in 3 ways, so a(4) = 1 + 3 = 4.
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PROG
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(PARI) my(N=25); M(N, 4)[2..1+N, 5]~ \\ See A339780 for M(n, m).
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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