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A171440
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Expansion of (1+x)^5/(1-x).
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9
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1, 6, 16, 26, 31, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32
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OFFSET
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0,2
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COMMENTS
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a(n)=2^5=32 for n>=5. We observe that this sequence is the transform of A171418 by T such that: T(u_0,u_1,u_2,u_3,u_4,u_5,...)=(u_0,u_0+u_1,u_1+u_2,u_2+u_3,u_3+u_4,...).
Also continued fraction expansion of (229657824-sqrt(257))/197139199. - Bruno Berselli, Sep 23 2011
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REFERENCES
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(Revue bimestrielle), Richard Choulet, Une nouvelle formule de combinatoire?, Mathematique et Pedagogie, 157 (2006), p. 53-60.
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LINKS
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Vincenzo Librandi, Table of n, a(n) for n = 0..100
Index to sequences with linear recurrences with constant coefficients, signature (1).
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FORMULA
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With m=6, a(n)=sum(C(m,n-2*k),k=0..floor(n/2)).
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EXAMPLE
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a(4)=C(6,4-0)+C(6,4-2)+C(6,4-4)=15+15+1=31
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CROSSREFS
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Cf. A040000, A113311, A115291, A171418, A171441, A171442, A171443.
Sequence in context: A034053 A199988 A114222 * A031220 A011536 A043513
Adjacent sequences: A171437 A171438 A171439 * A171441 A171442 A171443
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KEYWORD
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nonn,easy
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AUTHOR
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Richard Choulet, Dec 09 2009
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EXTENSIONS
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Definition rewritten by Bruno Berselli, Sep 23 2011
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STATUS
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approved
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