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A052183
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A second order recursive sequence.
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0
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2, 3, 12, 60, 330, 1911, 11424, 69768, 432630, 2713425, 17168580, 109390320, 700939512, 4512458580, 29164264320, 189120846288, 1229917589262, 8018580361365, 52392620853300, 342991368096300, 2249282417749290
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| c(2; n) is equivalent to Eq. (6.22) on p. 129 of the Carlitz reference.
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REFERENCES
| L. Carlitz, Enumeration of two-line arrays, Fib. Quart., 11 (1973), pps. 113-130.
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FORMULA
| a(n) = (n+2)*c(2; n), where c(2; n)=C(3n, n)/(2n+1) (A001764).
G.f.: (2-5*g)/((3*g-1)*(g-1)) where g*(1-g)^2 = x. - Mark van Hoeij, Nov 10 2011
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CROSSREFS
| Cf. A001764 and A000108.
Sequence in context: A094532 A092980 A191464 * A123899 A188588 A032133
Adjacent sequences: A052180 A052181 A052182 * A052184 A052185 A052186
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KEYWORD
| easy,nonn
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AUTHOR
| Barry E. Williams, Jan 27 2000
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EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jan 31 2000
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