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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A376988 Number of polycubes of size n and symmetry class EF.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 1, 2, 3, 6, 7, 13, 20, 32, 43, 71, 109, 162, 226, 363, 553, 811
Offset: 1

Views

Author

John Mason, Oct 13 2024

Keywords

Comments

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

Crossrefs

A376989 Number of polycubes of size n and symmetry class EFF.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 2, 1, 2, 4, 9, 8, 13, 19, 42, 37, 65, 78, 181, 152, 298
Offset: 1

Views

Author

John Mason, Oct 13 2024

Keywords

Comments

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

Crossrefs

A376990 Number of polycubes of size n and symmetry class CF.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 3, 2, 2, 1, 0, 0, 8, 4, 6, 4, 1, 0, 24, 11, 15, 10, 4, 1, 77, 32
Offset: 1

Views

Author

John Mason, Oct 13 2024

Keywords

Comments

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

Crossrefs

A376991 Number of polycubes of size n and symmetry class BBC.

Original entry on oeis.org

0, 1, 1, 2, 2, 1, 1, 2, 4, 2, 5, 7, 8, 5, 10, 15, 20, 12, 23, 36, 48, 30
Offset: 1

Views

Author

John Mason, Oct 13 2024

Keywords

Comments

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

Crossrefs

A377127 Number of polycubes of size n and symmetry class AB.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 0, 14, 4, 2
Offset: 1

Views

Author

John Mason, Oct 17 2024

Keywords

Comments

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

Crossrefs

A377131 Number of polycubes of size n and symmetry class R.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 12
Offset: 1

Views

Author

John Mason, Oct 17 2024

Keywords

Comments

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

Crossrefs

A038386 Number of "connected animals" formed from n 4-gon or 6-gon connected truncated octahedra in the b.c.c. lattice, allowing only translation of the lattice.

Original entry on oeis.org

1, 7, 67, 734, 8716, 109070, 1416284, 18903142, 257718235, 3573580367
Offset: 1

Views

Author

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

Keywords

Crossrefs

Extensions

More terms from Achim Flammenkamp
Name corrected and a(9)-a(10) from Aaron N. Siegel, May 31 2022

A122675 Number of "fragments" with n nodes generated from the simple cubic lattice.

Original entry on oeis.org

1, 1, 2, 9, 29, 165, 962, 6423
Offset: 1

Views

Author

N. J. A. Sloane, Sep 23 2006

Keywords

Comments

The "fragments" are generated as follows. For each of the polycubes with n cells, counted by A000162(n) or b(n) = A038119(n), consider two possible ways to inscribe a tetrahedron into each cell so that the tetrahedra in any two neighboring cells share an edge. The centers of the cells correspond to cations in the antifluorite structure, while the vertices of the tetrahedra correspond to anions. a(n) is the number of resulting tetrahedral clusters; enantiomorphic pairs are counted as one. Thus b(n) <= a(n) <= 2*b(n). - Andrey Zabolotskiy, Mar 04 2023

Crossrefs

A272385 Number of polycubes with n cells, allowing vertex connections and edge connections as well as face connections, distinguishing mirror images.

Original entry on oeis.org

1, 3, 16, 246, 4866, 115520, 2873712, 73884172, 1941259395
Offset: 1

Views

Author

George Sicherman, Apr 28 2016

Keywords

Examples

			For n=2 there are three possibilities: the two cubes share a face, or only an edge, or only a vertex.
For n=3, there are 14 tricubes allowing vertex, edge, and face connections. Two of them have distinct mirror images, so a(3) = 16.
		

Crossrefs

Cf. A272368 (identifying mirror images), A270862 (no vertex connections), A000162 (face connections only).

Extensions

a(8) and a(9) from Joerg Arndt, Dec 13 2023

A346958 a(n) is the minimal number of cubes required to make a void of volume n.

Original entry on oeis.org

6, 10, 13, 15, 17, 18, 18, 21, 23, 25, 26, 26
Offset: 1

Views

Author

Mohammed Yaseen, Aug 08 2021

Keywords

Comments

Following is an illustration of the first few voids in the form of polycubes (where an o represents a continuation upwards and an x represents a continuation downwards) each of which can be made by concealing it with a(n) cubes.
.---. .---.
| | | |
.---. .---.---. .---.---. .---.---.
| | | | | | | | | | o |
.---. .---.---. .---.---. .---.---.
n=1 n=2 n=3 n=4
.---. .---. .---.
| | | | | |
.---.---. .---.---.---. .---.---.---.
| | o | | | o | | | | ox| |
.---.---. .---.---.---. .---.---.---.
| | | | | |
.---. .---. .---.
n=5 n=6 n=7
Equivalently, the minimum perimeter size of any polycube of size n. - Sean A. Irvine, Aug 23 2021
Conjecture: When n is in A001845 the void is an octahedral crystal ball of volume n = A001845(m), which is concealed by a(n) = A005899(m+1) cubes. So a(A001845(m)) = A005899(m+1), m>=0. For example, a(1)=6 and a(7)=18. - Mohammed Yaseen, Sep 15 2022

Examples

			A cube-shaped void can be made by concealing it with 6 cubes, which is the minimal number to do so. So a(1)=6.
A dicube-shaped void can be made by concealing it with 10 cubes, which is the minimal number to do so. So a(2)=10.
		

Crossrefs

Cf. A261491 (2D analog).

Formula

a(n) < A193416(n) for n>2.

Extensions

a(8)-a(12) from Sean A. Irvine, Aug 23 2021
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