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A075167
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Number of edges in each rooted plane tree produced with the unranking algorithm presented in A075166, which is based on prime factorization.
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11
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0, 1, 2, 2, 3, 3, 4, 3, 3, 4, 5, 4, 6, 5, 4, 3, 7, 4, 8, 5, 5, 6, 9, 4, 4, 7, 4, 6, 10, 5, 11, 4, 6, 8, 5, 5, 12, 9, 7, 5, 13, 6, 14, 7, 5, 10, 15, 5, 5, 5, 8, 8, 16, 5, 6, 6, 9, 11, 17, 6, 18, 12, 6, 4, 7, 7, 19, 9, 10, 6, 20, 5, 21, 13, 5, 10, 6, 8, 22, 6, 4, 14, 23, 7, 8, 15, 11, 7, 24, 6, 7, 11
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OFFSET
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1,3
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COMMENTS
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Each n occurs A000108(n) times in total.
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LINKS
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FORMULA
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Other identities.
For all n >= 1, a(n) = A000120(A075165(n)). [Thus also the binary weight of A075165(n), because half of the bits are zeros.]
(End)
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PROG
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(Scheme, with memoization-macro definec)
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CROSSREFS
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A253782 gives the positions where this sequence differs from A252464 (first time at n=16).
Cf. A000108, A000120, A029837, A055642, A051119, A061395, A071178, A075165, A075166, A106442, A253783.
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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