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A038086
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Number of n-node rooted identity trees of height at most 7.
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3
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1, 1, 1, 2, 3, 6, 12, 25, 51, 105, 211, 421, 832, 1641, 3224, 6328, 12382, 24200, 47197, 91915, 178683, 346897, 672443, 1301850, 2517078, 4860938, 9376300, 18066270, 34772627, 66859667, 128427832, 246456677, 472519632, 905131358
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OFFSET
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1,4
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COMMENTS
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The number of terms is A038093(7), a number that is too large to write down!
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LINKS
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Table of n, a(n) for n=1..34.
N. J. A. Sloane, Transforms
Index entries for sequences related to rooted trees
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FORMULA
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Take Weigh transform of A038085 and shift right.
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MAPLE
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weigh:= proc (p) proc(n) local x, k; coeff (series (mul ((1+x^k)^p(k), k=1..n), x, n+1), x, n) end end: wsh:= p-> n-> weigh(p)(n-1): a:= (wsh@@4) (n-> `if`(n>0 and n<12, [1$3, 2$5, 1$3][n], 0)): seq (a(n), n=1..34); [From Alois P. Heinz, Sep 10 2008]
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CROSSREFS
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Cf. A038081-A038093.
Sequence in context: A187741 A216632 A077903 * A032305 A032218 A005829
Adjacent sequences: A038083 A038084 A038085 * A038087 A038088 A038089
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KEYWORD
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nonn,fini
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AUTHOR
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Christian G. Bower, Jan 04 1999.
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STATUS
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approved
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