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.

A066158 Number of fixed polyominoes with n cells and tree-like structure.

Original entry on oeis.org

1, 2, 6, 18, 55, 174, 570, 1908, 6473, 22202, 76886, 268352, 942651, 3329608, 11817582, 42120340, 150682450, 540832274, 1946892842, 7027047848, 25424079339, 92185846608, 334925007128, 1219054432490, 4444545298879, 16229462702152, 59347661054364
Offset: 1

Views

Author

Jan Kristian Haugland, Dec 13 2001

Keywords

Comments

Computed by a modified version of the program used for A065068.
Aleksandrowicz and Barequet (2011) confirm first 27 terms. - Gill Barequet, May 25 2011

References

  • G. Aleksandrowicz and G. Barequet, Parallel enumeration of lattice animals, Proc. 5th Int. Frontiers of Algorithmics Workshop, Zhejiang, China, Lecture Notes in Computer Science, 6681, Springer-Verlag, 90-99, May 2011.
  • N. Madras, C. E. Soteros, S. G. Whittington, J. L. Martin, M. F. Sykes et al., The free energy of a collapsing branched polymer, J. Phys. A: Math. Gen. 23 (1990) 5327-5350.

Crossrefs

Cf. A001168 (fixed polyominoes), A019441 (coefficients of g.f. related to this sequence), A118356, A191094, A191095, A191096, A191097, A191098 (fixed tree-like polycubes in 3, 4, 5, 6, 7, and 8 dimensions, resp.).

Extensions

Added a(18) and a(19) from Madras et al. - R. J. Mathar, Apr 08 2006
Terms from a(20) on added by N. J. A. Sloane, Nov 05 2008, from the Jensen paper.

A191094 Number of n-cell fixed tree-like polycubes in 4 dimensions.

Original entry on oeis.org

1, 4, 28, 228, 2018, 18892, 184400, 1857856, 19189675, 202214452
Offset: 1

Views

Author

Gill Barequet, May 25 2011

Keywords

References

  • G. Aleksandrowicz and G. Barequet, Parallel enumeration of lattice animals, Proc. 5th Int. Frontiers of Algorithmics Workshop, Zhejiang, China, Lecture Notes in Computer Science, 6681, Springer-Verlag, 90-99, May 2011.

Crossrefs

Cf. A066158 (fixed tree-like polyominoes), A118356, A191095, A191096, A191097, A191098 (fixed tree-like polycubes in 3, 5, 6, 7, and 8 dimensions, resp.).

A191095 Number of n-cell fixed tree-like polycubes in 5 dimensions.

Original entry on oeis.org

1, 5, 45, 485, 5775, 73437, 979335, 13536225, 192393410, 2796392165
Offset: 1

Views

Author

Gill Barequet, May 25 2011

Keywords

References

  • G. Aleksandrowicz and G. Barequet, Parallel enumeration of lattice animals, Proc. 5th Int. Frontiers of Algorithmics Workshop, Zhejiang, China, Lecture Notes in Computer Science, 6681, Springer-Verlag, 90-99, May 2011.

Crossrefs

Cf. A066158 (fixed tree-like polyominoes), A118356, A191094, A191096, A191097, A191098 (fixed tree-like polycubes in 3, 4, 6, 7, and 8 dimensions, resp.).

A191096 Number of n-cell fixed tree-like polycubes in 6 dimensions.

Original entry on oeis.org

1, 6, 66, 886, 13281, 213978, 3630090, 64012932
Offset: 1

Views

Author

Gill Barequet, May 25 2011

Keywords

References

  • G. Aleksandrowicz and G. Barequet, Parallel enumeration of lattice animals, Proc. 5th Int. Frontiers of Algorithmics Workshop, Zhejiang, China, Lecture Notes in Computer Science, 6681, Springer-Verlag, 90-99, May 2011.

Crossrefs

Cf. A066158 (fixed tree-like polyominoes), A118356, A191094, A191095, A191097, A191098 (fixed tree-like polycubes in 3, 4, 5, 7, and 8 dimensions, resp.).

A191097 Number of n-cell fixed tree-like polycubes in 7 dimensions.

Original entry on oeis.org

1, 7, 91, 1463, 26460, 516691, 10654378
Offset: 1

Views

Author

Gill Barequet, May 25 2011

Keywords

References

  • G. Aleksandrowicz and G. Barequet, Parallel enumeration of lattice animals, Proc. 5th Int. Frontiers of Algorithmics Workshop, Zhejiang, China, Lecture Notes in Computer Science, 6681, Springer-Verlag, 90-99, May 2011.

Crossrefs

Cf. A066158 (fixed tree-like polyominoes), A118356, A191094, A191095, A191096, A191098 (fixed tree-like polycubes in 3, 4, 5, 6, and 8 dimensions, resp.).

A191098 Number of n-cell fixed tree-like polycubes in 8 dimensions.

Original entry on oeis.org

1, 8, 120, 2248, 47636, 1088017, 26424957
Offset: 1

Views

Author

Gill Barequet, May 25 2011

Keywords

References

  • G. Aleksandrowicz and G. Barequet, Parallel enumeration of lattice animals, Proc. 5th Int. Frontiers of Algorithmics Workshop, Zhejiang, China, Lecture Notes in Computer Science, 6681, Springer-Verlag, 90-99, May 2011.

Crossrefs

Cf. A066158 (fixed tree-like polyominoes), A118356, A191094, A191095, A191096, A191097 (fixed tree-like polycubes in 3, 4, 5, 6, and 7 dimensions, resp.).

A304196 Number of free tree-like polycubes of size n in three dimensions.

Original entry on oeis.org

1, 1, 2, 6, 21, 91, 484, 2817, 17788, 116741, 788081, 5414701, 37703459, 265182187
Offset: 1

Views

Author

Lotfi Bouallagui, May 07 2018

Keywords

Comments

A free tree-like polycube of size n in three dimensions is a face-connected set of n cells in the cubic lattice, up to translation, rotation and reflection, whose dual graph has no cycles.

Crossrefs

Cf. A118356 (fixed tree-like 3d-polycubes), A304198 (free tree-like 4d-polycubes), A131482 (free tree-like polyominoes).

Extensions

Terms a(13) and a(14) from Joerg Arndt and Márk Péter Légrádi, May 21 2023

A363199 Number of free tree-like polycubes of size n, identifying rotations but not reflections.

Original entry on oeis.org

1, 1, 2, 7, 27, 138, 822, 5154, 33880, 227495, 1554266, 10749089, 75106906
Offset: 1

Views

Author

Keywords

Comments

Tree-like means that the graph connecting midpoints of adjacent cubes is a tree.
Additionally identifying reflections gives A304196.
The fixed version is A118356.

Extensions

a(12) and a(13) from Joerg Arndt, Dec 11 2023
Showing 1-8 of 8 results.