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A339785
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Number of homeomorphically irreducible leaf colored trees with n leaves using exactly 2 colors.
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4
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0, 1, 2, 7, 24, 91, 354, 1491, 6504, 29711, 139616, 674696, 3328798, 16730955, 85382210, 441571216, 2310003732, 12206975528, 65082858008, 349756996762, 1892980028014, 10310987833049, 56489307860860, 311112321625754, 1721692801914844, 9569930999155801, 53410232801675436
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OFFSET
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1,3
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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, 2)-2*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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