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A339786
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Number of homeomorphically irreducible leaf colored trees with n leaves using exactly 3 colors.
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3
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0, 0, 1, 9, 63, 412, 2673, 17571, 117365, 798819, 5530122, 38908380, 277750749, 2009160864, 14707923021, 108835512411, 813241695330, 6130521151377, 46584949832013, 356571373433217, 2747371943624943, 21296479544449677, 165994877608025730, 1300408539157086640
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OFFSET
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1,4
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LINKS
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FORMULA
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PROG
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(PARI) my(N=25); (U(N, 3) - 3*U(N, 2) + 3*U(N, 1))[2..1+N] \\ See A339780 for U(n, k).
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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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