cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A096419 Number of cyclically symmetric plane partitions (Macdonald's plane partition conjecture).

Original entry on oeis.org

1, 0, 0, 1, 0, 0, 2, 1, 0, 2, 1, 0, 4, 3, 0, 5, 4, 0, 8, 8, 0, 10, 11, 0, 15, 19, 1, 20, 27, 1, 28, 43, 3, 36, 61, 6, 50, 92, 11, 64, 129, 18, 86, 189, 33, 110, 262, 51, 145, 374, 84, 184, 514, 129, 238, 718, 201, 300, 977, 300, 384, 1344, 454, 482, 1812, 661, 609, 2459, 972
Offset: 1

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Author

Wouter Meeussen, Aug 08 2004

Keywords

Comments

Equals A048141 (C3v symmetry) + 2* A048142 (only C3 symmetry).

References

  • Andrews, G. E. "Plane Partitions (III): The Weak Macdonald Conjecture." Invent. Math. 53, 193-225, 1979.
  • Mills, W. H.; Robbins, D. P.; and Rumsey, H. Jr., Proof of the Macdonald Conjecture. Invent. Math. 66, 73-87, 1982.

Crossrefs

Programs

  • Mathematica
    len=151;m=Ceiling[len/3];mcdon=Rest@CoefficientList[Series[Product[(1-q^(3i-1))/(1-q^(3i-2)) Product[(1-q^(3(m+i+j-1)))/(1-q^(3(2i+j-1))), {j, i, m}], {i, 1, m}], {q, 0, len}], q] (* updated by Wouter Meeussen, Apr 15 2025 *)

Formula

See Mathematica code for a formula.

A048139 Number of planar partitions of n, when partitions that are rotations of each other (when regarded as 3-D objects) are counted only once.

Original entry on oeis.org

1, 1, 2, 5, 8, 16, 30, 54, 94, 168, 287, 493, 831, 1391, 2293, 3769, 6114, 9867, 15782, 25098, 39598, 62165, 96935, 150398, 232021, 356261, 544220, 827758, 1253222, 1889655, 2837455, 4244505, 6324993, 9392009, 13897056, 20494991, 30126628
Offset: 1

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Author

Keywords

Comments

Plane partitions seen as 3-dimensional-objects can have a threefold symmetry axis.

Examples

			n=3 gives 2 forms: {{3}}={{1,1,1}}={{1},{1},{1}} and {{2,1}}={{1,1},{1}}={{2},{1}}.
		

Crossrefs

Equals Cs + 2 C1 + 2 C3 + C3v, Cs=A000784, C1=A000785, C3=A048142, C3v=A048141. Cf. A000219, A005987.
Or, equals (2*A048141+A000219+4*A048142)/3.

Extensions

Edited by N. J. A. Sloane, Oct 26 2008 at the suggestion of R. J. Mathar.
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