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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A002841 Number of 3-connected self-dual planar graphs with 2n edges.

Original entry on oeis.org

1, 1, 2, 6, 16, 50, 165, 554, 1908, 6667, 23556, 84048, 302404, 1095536, 3993623
Offset: 3

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Author

Keywords

Comments

Also number of self-dual polyhedra with n+1 vertices (and n+1 faces). - Franklin T. Adams-Watters, Dec 18 2006

References

  • M. B. Dillencourt, Polyhedra of small orders and their Hamiltonian properties. Tech. Rep. 92-91, Info. and Comp. Sci. Dept., Univ. Calif. Irvine, 1992.
  • 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).

Crossrefs

Cf. A000944.

Extensions

Definition corrected by Gordon F. Royle, Dec 15 2005
a(14)-a(17) added by Jan Goedgebeur, Sep 16 2021

A006759 Number of one-sided strictly 3-dimensional polyominoes with n cells.

Original entry on oeis.org

0, 0, 0, 3, 17, 131, 915, 6553, 47026, 341888, 2505449, 18534827, 138224058, 1038594326, 7856087894, 59782042225, 457359506070, 3515816578512, 27143401299351, 210372490707568
Offset: 1

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Author

Keywords

References

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

Crossrefs

A column of A195738.

Programs

  • Mathematica
    A[s_Integer] := With[{s6 = StringPadLeft[ToString[s], 6, "0"]}, Cases[ Import["https://oeis.org/A" <> s6 <> "/b" <> s6 <> ".txt", "Table"], {, }][[All, 2]]];
    A000105 = A@000105;
    A000162 = A@000162;
    a[n_] := A000162[[n]] - A000105[[n + 1]];
    a /@ Range[16] (* Jean-François Alcover, Jan 16 2020 *)

Extensions

a(11) corrected and a(13)-a(16) from A000162-A000105 by Jean-François Alcover, Jan 16 2020
Name clarified and a(17)-a(20) from A000162-A000105 by John Mason, Dec 26 2023

A038172 Number of "connected animals" formed from n rhombic dodecahedra (or edge-connected cubes) in the face-centered cubic lattice, allowing translation and rotations of the lattice.

Original entry on oeis.org

1, 1, 5, 28, 225, 2274, 24955, 286143, 3367443, 40358811, 490598186
Offset: 1

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Crossrefs

Extensions

This extends earlier work of Torsten Sillke (TORSTEN.SILLKE(AT)LHSYSTEMS.COM). Added the 10th term.
a(11) from Joerg Arndt and Márk Péter Légrádi, Apr 30 2023

A038180 Number of "connected animals" formed from n square- or hexagon-connected truncated octahedra in the b.c.c. lattice, allowing translation and rotations of the lattice.

Original entry on oeis.org

1, 2, 6, 44, 394, 4680, 59361, 789303, 10742595, 148921162, 2093400002, 29769338104
Offset: 1

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Author

Torsten Sillke (TORSTEN.SILLKE(AT)LHSYSTEMS.COM)

Keywords

Crossrefs

Extensions

Corrected and extended by Achim Flammenkamp
Definition corrected by Fred Bayer, Aug 11 2010
More terms from Mark Owen, Oct 11 2013

A270862 Number of polycubes with n cells, allowing edge connections as well as face connections, distinguishing mirror images.

Original entry on oeis.org

1, 2, 9, 88, 1103, 17570, 295506, 5168034, 92436673
Offset: 1

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Author

George Sicherman, Mar 24 2016

Keywords

Examples

			a(3)=9 because there are 8 ways to join 3 cells in the cubic grid at faces or edges, identifying reflections, and one of those 8 has distinct mirror images, which makes 9.
		

References

  • Jørgen Lou, Danish Patent 126840 (27 August 1973).

Crossrefs

Cf. A268666 (identifying mirror images), A000162, A030222 (2-dimensional polyplets).

Extensions

Terms a(8) and a(9) from Joerg Arndt and Márk Péter Légrádi, May 20 2023

A292065 Number of Besźel [Beszel] Polycubes with n cells, distinguishing mirror images. A Besźel polycube is a polycube whose cells each have two or more even coordinates.

Original entry on oeis.org

1, 1, 2, 4, 12, 27, 106, 339, 1336, 5029
Offset: 1

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Author

George Sicherman, Sep 08 2017

Keywords

Comments

This sequence also gives the number of Ul Qoma Polycubes with n cells. An Ul Qoma polycube is a polycube whose cells each have two or more odd coordinates.

Examples

			a(4) = 4 because 4 of the 8 tetracubes (I, L, T, K) can be embedded in the Besźel section of the cubic grid.
		

References

  • China Miéville, The City & the City, Macmillan, 2009.

Crossrefs

Cf. A292157: Number of Besźel Polycubes with n cells, identifying mirror images; A000162: Number of polycubes with n cells [distinguishing mirror images].

A355966 Number of 3-dimensional polyominoes (or polycubes) with n cells that have cavities (inclusions of empty space).

Original entry on oeis.org

20, 404, 6164, 75917, 835491
Offset: 11

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Author

Gleb Ivanov, Jul 21 2022

Keywords

Comments

Even if two polycubes are mirror images of each other, they are considered different for this sequence.
Polycubes with less than 11 cells can't have cavities.
Largest enclosed volume >= A355880(n-5) for polycubes with n cells.

Crossrefs

Cf. A357083 (without distinguished reflections).

A376964 Number of polycubes of size n and symmetry class I (no symmetry).

Original entry on oeis.org

0, 0, 0, 0, 4, 46, 394, 3025, 22707, 167732, 1241417, 9221624, 68936674, 518574100, 3925132946, 29878869619, 228629549175, 1757697391087, 13570818452472, 105182527335313, 818093680980786, 6383353461322488
Offset: 1

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Author

John Mason, Oct 11 2024

Keywords

Comments

See link "Counting free polycubes" for explanation of notation.

Crossrefs

A376965 Number of polycubes of size n and symmetry class A.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 2, 22, 14, 31, 41, 213, 182, 321, 453, 1796
Offset: 1

Views

Author

John Mason, Oct 11 2024

Keywords

Comments

See link "Counting free polycubes" for explanation of notation.

Crossrefs

A376966 Number of polycubes of size n and symmetry class B.

Original entry on oeis.org

0, 0, 0, 0, 0, 3, 4, 37, 52, 342, 502, 2836, 4343, 22622, 35405, 176176, 281141, 1363112, 2205171, 10527712, 17221126, 81462884, 134424679, 632308448
Offset: 1

Views

Author

John Mason, Oct 11 2024

Keywords

Comments

See link "Counting free polycubes" for explanation of notation.

Crossrefs

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