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.

Showing 1-8 of 8 results.

A056932 Antichains (or order ideals) in the poset 2*2*2*n or size of the distributive lattice J(2*2*2*n).

Original entry on oeis.org

1, 20, 168, 887, 3490, 11196, 30900, 75966, 170379, 354640, 693836, 1288365, 2287844, 3908776, 6456600, 10352796, 16167765, 24660252, 36824128, 53943395, 77656326, 110029700, 153644140, 211691610, 288086175, 387589176, 515950020, 680063833, 888147272
Offset: 0

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Comments

a(n) is the number of order preserving maps from B_3 into [n+1]. a(n) is also the number of length n+1 multichains from bottom to top in J(B_3). See Stanley reference for bijections with description in title. - Geoffrey Critzer, Jan 07 2021

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.
  • R. P. Stanley, Enumerative Combinatorics, Volume I, Second Edition, page 256, Proposition 3.5.1.

Crossrefs

Programs

  • Mathematica
    Table[48*Binomial[n+8,8] - 96*Binomial[n+7,7] + 63*Binomial[n+6,6] - 15*Binomial[n+5,5] + Binomial[n+4,4], {n, 0, nn}] (* T. D. Noe, May 29 2012 *)

Formula

a(n) = 48*C(n+8, 8) - 96*C(n+7, 7) + 63*C(n+6, 6) - 15*C(n+5, 5) + C(n+4, 4).
G.f.: (1+11*x+24*x^2+11*x^3+x^4)/(1-x)^9. [Berman and Koehler]

A006360 Antichains (or order ideals) in the poset 2*2*3*n or size of the distributive lattice J(2*2*3*n).

Original entry on oeis.org

1, 50, 887, 8790, 59542, 307960, 1301610, 4701698, 14975675, 43025762, 113414717, 277904900, 639562508, 1393844960, 2896063220, 5768600412, 11066514565, 20526933442, 36936277875, 64660182026, 110394412610
Offset: 0

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Author

Keywords

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

Crossrefs

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

Extensions

More terms from Mitch Harris, Jul 16 2000

A006362 Antichains (or order ideals) in the poset 2*2*5*n or size of the distributive lattice J(2*2*5*n).

Original entry on oeis.org

1, 196, 11196, 307960, 5157098, 60112692, 530962446, 3764727340, 22326282261, 114158490576, 515063238810, 2087929609236, 7714649716552, 26285397502428, 83379798088110, 248202756212336, 697998155989501, 1864955619299196
Offset: 0

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Author

Keywords

References

  • J. Berman and P. Koehler, Cardinalities of finite distributive lattices, Mitteilungen aus dem Mathematischen Seminar Giessen, 121 (1976), 103-124.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Extensions

More terms from Mitch Harris, Jul 16 2000

A056933 Antichains (or order ideals) in the poset 2*2*6*n or size of the distributive lattice J(2*2*6*n).

Original entry on oeis.org

1, 336, 30900, 1301610, 32046856, 530962446, 6479344016, 61951251333, 485198553532, 3217462615688, 18528857431906, 94529315562186, 434088353496446, 1817613939845670, 7014049051387480, 25167786776727516
Offset: 0

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Keywords

References

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

Crossrefs

A056934 Antichains (or order ideals) in the poset 2*2*7*n or size of the distributive lattice J(2*2*7*n).

Original entry on oeis.org

1, 540, 75966, 4701698, 164489084, 3764727340, 61951251333, 782318812002, 7946895019096, 67270102239520, 487605585591870, 3092040981805272, 17451258588313354, 88902214572208640, 413569247116248032
Offset: 0

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References

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

Crossrefs

A056935 Antichains (or order ideals) in the poset 2*3*3*n or size of the distributive lattice J(2*3*3*n).

Original entry on oeis.org

1, 175, 8790, 211250, 3092808, 31635580, 246441430, 1549486490, 8192995479, 37548347569, 152602439244, 559835910940, 1880152558980, 5846268790220, 16988036626948, 46486024648180, 120562654732065, 297976456047575
Offset: 0

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Author

Keywords

References

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

Crossrefs

A056936 Antichains (or order ideals) in the poset 2*3*4*n or size of the distributive lattice J(2*3*4*n).

Original entry on oeis.org

1, 490, 59542, 3092808, 89613429, 1691136270, 22954776044, 239831111938, 2024703039198, 14318216628378, 87184226214168, 467034400160664, 2239064967256060, 9741467994941264, 38902816410160608
Offset: 0

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References

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

Crossrefs

A056937 Number of antichains (or order ideals) in the poset 3*3*3*n or size of the distributive lattice J(3*3*3*n).

Original entry on oeis.org

1, 980, 211250, 17792748, 781429368, 21238316210, 398925639186, 5585711269074, 61555624183223, 555895303974238, 4242859829536322, 28038281717424550, 163544036697306396, 855242362045150398
Offset: 0

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Author

Keywords

References

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

Crossrefs

Showing 1-8 of 8 results.