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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

N. J. A. Sloane.

EXTENSIONS

More terms from Wolfdieter Lang

STATUS

approved

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Last modified December 16 18:04 EST 2018. Contains 318188 sequences. (Running on oeis4.)