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A000432
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Series-parallel numbers.
(Formerly M4538 N1926)
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0
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8, 52, 288, 1424, 6648, 29700, 128800, 545600, 2269672, 9303140, 37672216, 150998016, 599988696, 2366216164, 9270987656, 36116062832, 139978757920, 540069059028, 2075217121688, 7944690769952, 30313624200640, 115312027433188, 437420730644304, 1655047867097280, 6247339311097296, 23530440547115428, 88447214709073696, 331832490378209152, 1242766581420901656, 4646714574562484628, 17347357264162110368, 64668460220964604944, 240747014238189337840, 895102104022837748484, 3323982608759454833032, 12329573838525875316560, 45684294664598118867184, 169098457957523787786644
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OFFSET
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3,1
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REFERENCES
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J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 142.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
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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Table of n, a(n) for n=3..40.
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FORMULA
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G.f.: 4(2+S)(1+S)/(1-S)^5, where S = g.f. for A000084. - Sean A. Irvine, Nov 14 2010
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MATHEMATICA
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n = 38; s = 1/(1 - x) + O[x]^(n + 1); Do[s = s/(1 - x^k)^Coefficient[s, x^k] + O[x]^(n + 1), {k, 2, n}] ; S = s - 1; CoefficientList[4 (2 + S) (1 + S)/(1 - S)^5 + O[x]^n, x] (* Jean-François Alcover, Feb 09 2016 *)
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CROSSREFS
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Sequence in context: A022732 A256047 A227732 * A153336 A080279 A279283
Adjacent sequences: A000429 A000430 A000431 * A000433 A000434 A000435
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane
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EXTENSIONS
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More terms from Sean A. Irvine, Nov 14 2010
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STATUS
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approved
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