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 A001762 Number of dissections of a ball. (Formerly M4741 N2029) 3
 1, 1, 10, 180, 4620, 152880, 6168960, 293025600, 15990004800, 984647664000, 67493121696000, 5094263446272000, 419688934689024000, 37465564582397952000, 3601861863990534144000, 370962724717928318976000, 40744403224500159055872000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,3 REFERENCES L. W. Beineke and R. E. Pippert, Enumerating labeled k-dimensional trees and ball dissections, pp. 12-26 of Proceedings of Second Chapel Hill Conference on Combinatorial Mathematics and Its Applications, University of North Carolina, Chapel Hill, 1970. Reprinted in Math. Annalen, 191 (1971), 87-98. 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 T. D. Noe, Table of n, a(n) for n = 3..100 L. W. Beineke and R. E. Pippert, The Number of Labeled Dissections of a k-Ball., Math. Annalen, 191 (1971), 87-98. FORMULA a(n) = binomial(n,3)*(3*n-9)!/(2*n-4)!, n >= 4; a(3) = 1. MATHEMATICA Join[{1}, Table[Binomial[n, 3]*(3*n - 9)!/(2*n - 4)!, {n, 4, 25}]] (* T. D. Noe, Aug 10 2012 *) CROSSREFS Cf. A001763. Sequence in context: A113119 A067416 A113671 * A034908 A030048 A318796 Adjacent sequences:  A001759 A001760 A001761 * A001763 A001764 A001765 KEYWORD nonn AUTHOR EXTENSIONS More terms from Wolfdieter Lang STATUS approved

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Last modified February 28 11:08 EST 2020. Contains 332323 sequences. (Running on oeis4.)