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A006360 Antichains (or order ideals) in the poset 2*2*3*n or size of the distributive lattice J(2*2*3*n)
(Formerly M5300)
8
1, 50, 887, 8790, 59542, 307960, 1301610, 4701698, 14975675, 43025762, 113414717, 277904900, 639562508, 1393844960, 2896063220, 5768600412, 11066514565, 20526933442, 36936277875, 64660182026, 110394412610 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

J. Berman and P. Koehler, Cardinalities of finite distributive lattices, Mitteilungen aus dem Mathematischen Seminar Giessen, 121 (1976), 103-124.

Manfred Goebel, Rewriting Techniques and Degree Bounds for Higher Order Symmetric Polynomials, Applicable Algebra in Engineering, Communication and Computing (AAECC), Volume 9, Issue 6 (1999), 559-573.

G. Kreweras, Les preordres totaux compatibles avec un ordre partiel. Math. Sci. Humaines No. 53 (1976), 5-30.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=0..20.

Index entries for sequences related to posets

FORMULA

Empirical G.f.: (x+1)*(x^6+36*x^5+279*x^4+594*x^3+279*x^2+36*x+1)/(1-x)^13. [Colin Barker, May 29 2012]

MATHEMATICA

MatrixPower[ ZetaP[ #, n + 1 ][ [ 1, Card[ # ] ] ]&@JofP[ Chain[ 2, 2, 3 ] ]

CROSSREFS

Cf. A000217, A000330, A050446, A050447, A006356, A006357, A006358, A006359, A000372, A056932, A006361, A006362, A056933, A056934, A056935, A056936, A056937.

Sequence in context: A086027 A110929 A101929 * A224059 A224045 A224276

Adjacent sequences:  A006357 A006358 A006359 * A006361 A006362 A006363

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Mitch Harris, Jul 16 2000

STATUS

approved

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Last modified April 24 02:19 EDT 2014. Contains 240947 sequences.