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 A000432 Series-parallel numbers. (Formerly M4538 N1926) 0
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,1 REFERENCES 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). LINKS FORMULA G.f.: 4(2+S)(1+S)/(1-S)^5, where S = g.f. for A000084. - Sean A. Irvine, Nov 14 2010 MATHEMATICA 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 *) CROSSREFS Sequence in context: A022732 A256047 A227732 * A153336 A080279 A279283 Adjacent sequences:  A000429 A000430 A000431 * A000433 A000434 A000435 KEYWORD nonn AUTHOR EXTENSIONS More terms from Sean A. Irvine, Nov 14 2010 STATUS approved

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Last modified January 19 21:52 EST 2019. Contains 319310 sequences. (Running on oeis4.)