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 1-6 of 6 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.

A118356 Number of clusters with n vertices, n-1 edges and zero contacts on the simple cubic lattice.

Original entry on oeis.org

1, 3, 15, 83, 486, 2967, 18748, 121725, 807381, 5447203, 37264974, 257896500, 1802312605, 12701190885, 90157130289, 644022007040, 4626159163233
Offset: 1

Views

Author

R. J. Mathar, May 14 2006

Keywords

Comments

a(n)<=A001931(n) due to the "no-contact" restriction.
An alternative wording for a(n) is the number of n-cell fixed tree-like polycubes in 3 dimensions. - 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.

Crossrefs

Cf. A066158 (fixed tree-like polyominoes), A191094, A191095, A191096, A191097, A191098 (fixed tree-like polycubes in 4, 5, 6, 7, and 8 dimensions, resp.).

Extensions

a(1)=1 added by Gill Barequet, May 25 2011

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.).

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.).
Showing 1-6 of 6 results.