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Search: id:A006632
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| A006632 |
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3*binomial(4*n-1,n-1)/(4*n-1).
(Formerly M2997)
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+0
9
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| 1, 3, 15, 91, 612, 4389, 32890, 254475, 2017356, 16301164, 133767543, 1111731933, 9338434700, 79155435870, 676196049060, 5815796869995, 50318860986108, 437662920058980, 3824609516638444, 33563127932394060, 295655735395397520, 2613391671568320765
(list; graph; listen)
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OFFSET
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1,2
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REFERENCES
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H. M. Finucan, Some decompositions of generalized Catalan numbers, pp. 275-293 of Combinatorial Mathematics IX. Proc. Ninth Australian Conference (Brisbane, August 1981). Ed. E. J. Billington, S. Oates-Williams and A. P. Street. Lecture Notes Math., 952. Springer-Verlag, 1982.
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LINKS
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INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 438
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FORMULA
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a(n) = binom[4n+3, n+1]/(4n+3) = 3 binom[4n+2, n] - binom[4n+2, n+1]. - David Callan (callan(AT)stat.wisc.edu), Sep 15 2004
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MATHEMATICA
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InverseSeries[Series[y*(1-y)^3, {y, 0, 24}], x] (* then A(x)=y(x)/x *) - Len Smiley Apr 07 2000
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CROSSREFS
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A112385 divided by 2.
Sequence in context: A077783 A047019 A099251 this_sequence A020018 A124553 A020108
Adjacent sequences: A006629 A006630 A006631 this_sequence A006633 A006634 A006635
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KEYWORD
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nonn
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AUTHOR
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Simon Plouffe (plouffe(AT)math.uqam.ca)
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