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A000786 Number of planar partitions of n.
(Formerly M1020 N0383)
10
1, 1, 2, 4, 6, 11, 19, 33, 55, 95, 158, 267, 442, 731, 1193, 1947, 3137, 5039, 8026, 12726, 20024, 31373, 48835, 75673, 116606, 178889, 273061, 415086, 628115, 946723, 1421082, 2125207, 3166152, 4700564, 6954151, 10254486, 15071903 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Partitions that are the same when regarded as 3-D objects are counted only once. - Wouter Meeussen

REFERENCES

P. A. MacMahon, Combinatory Analysis. Cambridge Univ. Press, London and New York, Vol. 1, 1915 and Vol. 2, 1916; see vol. 2, p 332.

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

Table of n, a(n) for n=1..37.

P. A. MacMahon, Combinatory analysis.

Eric Weisstein's World of Mathematics, Macdonald's Plane Partition Conjecture

FORMULA

Equals A000784+A000785+A048141+A048142.

Equals (A048141+3*A048140-A000219+2*A048142)/3. - Wouter Meeussen

CROSSREFS

Cf. A000784, A000785, A000219, A005987, A048142, A051056-A051061, A096419.

Sequence in context: A136424 A116732 A048239 * A289080 A000694 A164137

Adjacent sequences:  A000783 A000784 A000785 * A000787 A000788 A000789

KEYWORD

nonn,easy,nice

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Wouter Meeussen

STATUS

approved

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Last modified February 20 15:02 EST 2018. Contains 299380 sequences. (Running on oeis4.)