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Search: id:A006129
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| A006129 |
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a(0),a(1),a(2),... satisfy Sum a(k) binomial(n,k) (k=0..n) = 2^binomial(n,2), for n=0.1,...
(Formerly M3678)
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+0
10
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| 1, 0, 1, 4, 41, 768, 27449, 1887284, 252522481, 66376424160, 34509011894545, 35645504882731588, 73356937912127722841, 301275024444053951967648, 2471655539737552842139838345, 40527712706903544101000417059892
(list; graph; listen)
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OFFSET
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0,4
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COMMENT
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Also labeled graphs on n unisolated nodes (inverse binomial transform of A006125).
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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N. J. A. Sloane, Transforms
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FORMULA
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a(n)=sum_{k=0..n} (-1)^(n-k)*binomial(n, k)*2^binomial(k, 2).
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EXAMPLE
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2^binomial(n,2)=1+binomial(n,2)+4*binomial(n,3)+41*binomial(n,4)+768*binomial(n,5)+...
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CROSSREFS
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Sequence in context: A134277 A085340 A001908 this_sequence A022515 A059730 A006825
Adjacent sequences: A006126 A006127 A006128 this_sequence A006130 A006131 A006132
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KEYWORD
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nonn,nice,easy
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AUTHOR
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C. L. Mallows (colinm(AT)research.avayalabs.com)
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EXTENSIONS
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More terms and additional comments from Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 09 2000
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