A021103 -id:A021103 - cp's OEIS frontend

A000944 Number of polyhedra (or 3-connected simple planar graphs) with n nodes.

0, 0, 0, 1, 2, 7, 34, 257, 2606, 32300, 440564, 6384634, 96262938, 1496225352, 23833988129, 387591510244, 6415851530241, 107854282197058

Offset: 1

N. J. A. Sloane

H. T. Croft, K. J. Falconer and R. K. Guy, Unsolved Problems in Geometry, B15.
M. B. Dillencourt, Polyhedra of small orders and their Hamiltonian properties. Tech. Rep. 92-91, Info. and Comp. Sci. Dept., Univ. Calif. Irvine, 1992.
B. Grünbaum, Convex Polytopes. Wiley, NY, 1967, p. 424.
Y. Y. Prokhorov, ed., Mnogogrannik [Polyhedron], Mathematical Encyclopedia Dictionary, Soviet Encyclopedia, 1988.
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).
G. M. Ziegler, Questions about polytopes, pp. 1195-1211 of Mathematics Unlimited - 2001 and Beyond, ed. B. Engquist and W. Schmid, Springer-Verlag, 2001.

Gunnar Brinkmann and Brendan McKay, plantri and fullgen programs for generation of certain types of planar graph.
Gunnar Brinkmann and Brendan McKay, plantri and fullgen programs for generation of certain types of planar graph [Cached copy, pdf file only, no active links, with permission]
CombOS - Combinatorial Object Server, generate planar graphs
A. J. W. Duijvestijn and P. J. Federico, The number of polyhedral (3-connected planar) graphs, Math. Comp. 37 (1981), no. 156, 523-532. MR0243424 (39 #4746).
P. J. Federico, Enumeration of polyhedra: the number of 9-hedra, J. Combin. Theory, 7 (1969), 155-161.
Steven R. Finch, Mathematical Constants II, Encyclopedia of Mathematics and Its Applications, Cambridge University Press, Cambridge, 2018.
Lukas Finschi, A Graph Theoretical Approach for Reconstruction and Generation of Oriented Matroids, A dissertation submitted to the Swiss Federal Institute of Technology, Zurich for the degree of Doctor of Mathematics, 2001. See p. 155.
Moritz Firsching, Realizability and inscribability for simplicial polytopes via nonlinear optimization. Math. Program. 166, No. 1-2 (A), 273-295 (2017). Table 1
Komei Fukuda, Hiroyuki Miyata, and Sonoko Moriyama, Complete Enumeration of Small Realizable Oriented Matroids, arXiv:1204.0645 [math.CO], 2012; Discrete Comput. Geom. 49 (2013), no. 2, 359--381. MR3017917. - From _N. J. A. Sloane_, Feb 16 2013
Jorik Jooken, Computer-assisted graph theory: a survey, arXiv:2508.20825 [math.CO], 2025. See Ref. 196 at p. 5.
A. B. Korchagin, Ordering Cellular Spaces with Application to Curves and Knots, Discrete Comput. Geom., 40 (2008), 289-311.
G. P. Michon, Counting Polyhedra
Eric Weisstein's World of Mathematics, Polyhedral Graph

Cf. A005470, A049337, A049334, A003094, A049336, A021103, A005841.

Row sums of A212438.

More terms from Brendan McKay

a(18) from Brendan McKay, Jun 02 2006

A049337 Triangle read by rows: T(n,k) is the number of 3-connected planar graphs (or polyhedra) with n >= 1 nodes and 0 <= k <= C(n,2) edges.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 8, 11, 8, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 11, 42, 74, 76, 38, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 74, 296, 633, 768, 558, 219, 50

Offset: 1

Brendan McKay

			Triangle begins
  0;
  0,0;
  0,0,0,0;
  0,0,0,1,0,0,0;
  0,0,0,0,0,1,1,0,0,0;
  0,0,0,0,0,0,1,2,2,...;
  ...
From _Hugo Pfoertner_, Nov 24 2020: (Start)
Transposed table:
.
                              Nodes                        Sums
       4  5  6   7   8    9    10     11     12    13  14 |A002840
  Edges-+--+--+---+---+----+-----+------+------+-----+---+|-------
   6 | 1  .  .   .   .    .     .      .      .     .   . |      1
   7 | .  .  .   .   .    .     .      .      .     .   . |      0
   8 | .  1  .   .   .    .     .      .      .     .   . |      1
   9 | .  1  1   .   .    .     .      .      .     .   . |      2
  10 | .  .  2   .   .    .     .      .      .     .   . |      2
  11 | .  .  2   2   .    .     .      .      .     .   . |      4
  12 | .  .  2   8   2    .     .      .      .     .   . |     12
  13 | .  .  .  11  11    .     .      .      .     .   . |     22
  14 | .  .  .   8  42    8     .      .      .     .   . |     58
  15 | .  .  .   5  74   74     5      .      .     .   . |    158
  16 | .  .  .   .  76  296    76      .      .     .   . |    448
  17 | .  .  .   .  38  633   633     38      .     .   . |   1342
  18 | .  .  .   .  14  768  2635    768     14     .   . |   4199
  19 | .  .  .   .   .  538  6134   6134    558     .   . |  13384
  20 | .  .  .   .   .  219  8822  25626   8822   219   . |  43708
  21 | .  .  .   .   .   50  7916  64439  64439  7916  50 | 144810
  .. | .  .  .   .   .    .    ..     ..     ..    ..  .. |     ..
     ---+--+--+---+---+----+-----+------+-------+----+---+
  Sums 1  2  7  34 257 2606 32300 440564 6384634 .. A000944
(End)

Sean A. Irvine, Table of n, a(n) for n = 1..469; rows 1..14 flattened

Cf. A000944, A002840, A021103, A003094, A049334.
A049337, A058787, A212438 are all versions of the same triangle.
Cf. A058788.

Missing zeros inserted by Sean A. Irvine, Jul 29 2021

A034889 Number of embeddings on the sphere of 2-connected planar graphs with n nodes.

Original entry on oeis.org

1, 3, 10, 61, 564, 7593, 123874, 2262877, 44190279, 904777809, 19207129217, 419870351012, 9405626692325

Offset: 3

Ronald C. Read

The complete graph on two vertices is sometimes considered to be 2-connected (or nonseparable). Compare A002218 with A021103. - Andrew Howroyd, Mar 01 2021

R. C. Read and R. J. Wilson, An Atlas of Graphs, Oxford, 1998.

G. Brinkmann and B. D. McKay, Fast generation of planar graphs, MATCH Commun. Math. Comput. Chem, 58 (2007), 323-357. [Expanded version]
Eric Weisstein's World of Mathematics, Planar Embedding.

Row sums of A342060.

Cf. A002218, A005142, A021103.

a(8)-a(15) added by Mohammadreza Jooyandeh, Sep 03 2013

A049336 Table read by rows: T(n,k) = number of 2-connected planar graphs with n >= 1 nodes and 0 <= k <= 3n-6 edges.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 2, 3, 2, 1, 0, 0, 0, 0, 0, 0, 1, 3, 9, 13, 11, 5, 2, 0, 0, 0, 0, 0, 0, 0, 1, 4, 20, 49, 77, 75, 47, 16, 5, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 40, 158, 406, 662, 737, 538, 259, 72, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 7, 70, 426, 1645, 4176, 7307, 8871, 7541, 4353, 1671, 378, 50

Offset: 1

Brendan McKay

			Table begins:
  0;
  0, 0;
  0, 0, 0, 1;
  0, 0, 0, 0, 1, 1, 1;
  0, 0, 0, 0, 0, 1, 2, 3, 2,  1;
  0, 0, 0, 0, 0, 0, 1, 3, 9, 13, 11,  5,  2;
  0, 0, 0, 0, 0, 0, 0, 1, 4, 20, 49, 77, 75, 47, 16, 5;
  ...

Ruperto Corso, Table of n, a(n) for n = 1..249
A. Gagarin, G. Labelle, P. Leroux, and T. Walsh, Structure and enumeration of two-connected graphs with prescribed three-connected components, Adv. in Appl. Math. 43 (2009), no. 1, pp. 46-74.

Cf. A021103, A003094, A049334.

More terms, a(86) onwards, from Gilbert Labelle (labelle.gilbert(AT)uqam.ca), Jan 20 2009

A343869 Number of unlabeled nonseparable (or 2-connected) planar graphs with n edges.

Original entry on oeis.org

1, 0, 1, 1, 2, 4, 7, 16, 41, 108, 320, 1042, 3575, 13064, 49938, 197729, 805991, 3363084, 14302891, 61813285, 270805177, 1200460492, 5376709415, 24302430375, 110745093999, 508380790741

Offset: 1

Andrew Howroyd, May 04 2021

Terms may be computed using the tools geng and planarg in nauty.

Brendan McKay and Adolfo Piperno, nauty and Traces

Row sums of A343870.
Column sums of A049336(n > 1).
Cf. A002840 (3-connected), A010355, A021103, A046091, A289471, A291841.

# count graphs for the sequence by number of vertices v, sum over v afterwards
geng -C $v $n:$n | planarg -q | countg -q # Georg Grasegger, Jun 05 2023

a(21)-a(26) added by Georg Grasegger, Jun 05 2023

A187928 Number of embeddings on the sphere of planar graphs with n edges having connectivity exactly 2 and minimum vertex degree at least 3.

Original entry on oeis.org

1, 2, 4, 15, 42, 135, 440, 1480, 5106, 17890, 63264, 226018, 812354, 2936837, 10666188, 38901190, 142386358

Offset: 10

Stuart E Anderson, Mar 16 2011

The graphs are 2-connected, but not 3-connected. The graphs were enumerated using plantri (by B.D. McKay & G. Brinkmann) for the purpose of finding compound perfect squared squares. If all graphs with n edges are generated then all compound squares in order n-1 can be obtained from them. Graphs with minimum degree at least 3 are also called homeomorphically irreducible.

Stuart Anderson, Compound Perfect Squared Squares
B. D. McKay and G. Brinkmann, Plantri Guide
Gunnar Brinkmann and Brendan McKay, Guide to using plantri [Cached copy, with permission]

Antidiagonal sums of A378077.

Cf. A034889, A181340, A187927, A021103, A378076.

plantri
```
plantri -p -c2 -m3 -e# -x -u -v n
```

plantri -pc2m3e#xuv n # to count graphs by node number (n) and edge number (#)

a(22) corrected by Stuart E Anderson, Feb 24 2013
a(23)-a(26) from Lorenz Milla, Oct 08 2013
a(11) corrected by Andrew Howroyd, Nov 15 2024

A343870 Triangle read by rows: T(n,k) is the number of unlabeled nonseparable (or 2-connected) planar graphs with n edges and k nodes (n >= 1, 2 <= k <= n + 1).

Original entry on oeis.org

1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 3, 3, 1, 0, 0, 0, 0, 2, 9, 4, 1, 0, 0, 0, 0, 1, 13, 20, 6, 1, 0, 0, 0, 0, 0, 11, 49, 40, 7, 1, 0, 0, 0, 0, 0, 5, 77, 158, 70, 9, 1, 0, 0, 0, 0, 0, 2, 75, 406, 426, 121, 11, 1, 0, 0, 0, 0, 0, 0, 47, 662, 1645, 1018, 189, 13, 1, 0

Offset: 1

Andrew Howroyd, May 04 2021

			Triangle T(n,k) begins (n edges >= 1, k vertices >= 2):
  1;
  0, 0;
  0, 1, 0;
  0, 0, 1, 0;
  0, 0, 1, 1,  0;
  0, 0, 1, 2,  1,  0;
  0, 0, 0, 3,  3,  1,   0;
  0, 0, 0, 2,  9,  4,   1,   0;
  0, 0, 0, 1, 13, 20,   6,   1,   0;
  0, 0, 0, 0, 11, 49,  40,   7,   1,  0;
  0, 0, 0, 0,  5, 77, 158,  70,   9,  1, 0;
  0, 0, 0, 0,  2, 75, 406, 426, 121, 11, 1, 0;
  ...

Georg Grasegger, Table of n, a(n) for n = 1..351 (26 rows) (first 210 terms (20 rows) from Andrew Howroyd)

Row sums are A343869.
Column sums are A021103.
Cf. A049334, A049336 (transpose), A049337, A253186, A339070.

geng -C $k $n:$n | planarg -q | countg -q # Georg Grasegger, Jun 05 2023

T(n, n) = 1 for n >= 3.

T(n, n-1) = A253186(n-3) for n >= 3.

A049340 Triangle read by rows: T(n,k) is the number of planar graphs with n >= 1 nodes and 0 <= k <= binomial(n,2) edges, all degrees even.

Original entry on oeis.org

1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 3, 2, 2, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 3, 4, 4, 6, 5, 5, 3, 2, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 3, 4, 7, 9, 15, 17, 22, 14, 16, 5, 4, 0, 1, 0, 0, 0

Offset: 1

Brendan McKay

			Triangle begins:
  1;
  1, 0;
  1, 0, 0, 1;
  1, 0, 0, 1, 1, 0, 0;
  1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0;
  1, 0, 0, 1, 1, 1, 3, 2, 2, 1, 1, 0, 1, 0, 0, 0;
  ...

Sean A. Irvine, Table of n, a(n) for n = 1..231, rows 1..11 flattened
Sean A. Irvine, Java program (github)

Rows sums give A049339.

Cf. A000944, A021103, A003094, A049334.

Entry revised by Sean A. Irvine, Jul 29 2021

A361578 Number of 5-connected polyhedra (or 5-connected simple planar graphs) with n nodes.

Original entry on oeis.org

1, 0, 1, 1, 5, 8, 30, 85, 382, 1550, 7352

Offset: 12

Manfred Scheucher, Mar 16 2023

The icosahedral graph is the smallest 5-connected planar graph.

M. Kirchweger, M. Scheucher, and S. Szeider, SAT-Based Generation of Planar Graphs, in preparation.

Mathematics Stack Exchange -- What is the smallest 5-vertex-connected (5-edge-connected) planar graph?

Cf. A086216, A005470, A003094, A021103, A000944, A007027.

Cf. A049373 (planar graphs with minimum degree~5) and A111358 (5-connected planar trianguations)

A361369 Number of weakly 2-connected simple planar digraphs with n unlabeled nodes.

Original entry on oeis.org

7, 129, 6865, 774052

Offset: 3

Manfred Scheucher, Mar 09 2023

M. Kirchweger, M. Scheucher, and S. Szeider, SAT-Based Generation of Planar Graphs, in preparation.

Directed variant of A021103.

Cf. A000273, A003085, A361366-A361368

cp's OEIS Frontend

A000944 Number of polyhedra (or 3-connected simple planar graphs) with n nodes.

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A049337 Triangle read by rows: T(n,k) is the number of 3-connected planar graphs (or polyhedra) with n >= 1 nodes and 0 <= k <= C(n,2) edges.

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A034889 Number of embeddings on the sphere of 2-connected planar graphs with n nodes.

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A049336 Table read by rows: T(n,k) = number of 2-connected planar graphs with n >= 1 nodes and 0 <= k <= 3n-6 edges.

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A343869 Number of unlabeled nonseparable (or 2-connected) planar graphs with n edges.

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nauty

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A187928 Number of embeddings on the sphere of planar graphs with n edges having connectivity exactly 2 and minimum vertex degree at least 3.

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plantri

plantri

Extensions

A343870 Triangle read by rows: T(n,k) is the number of unlabeled nonseparable (or 2-connected) planar graphs with n edges and k nodes (n >= 1, 2 <= k <= n + 1).

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nauty

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A049340 Triangle read by rows: T(n,k) is the number of planar graphs with n >= 1 nodes and 0 <= k <= binomial(n,2) edges, all degrees even.

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Author

Keywords

Examples

Links

Crossrefs

Extensions

A361578 Number of 5-connected polyhedra (or 5-connected simple planar graphs) with n nodes.

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