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 1-9 of 9 results.

A319367 Triangle read by rows: T(n,k) is the number of simple vertex transitive graphs with n nodes and valency k, (0 <= k < n).

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 2, 2, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 2, 3, 3, 2, 1, 1, 1, 0, 2, 0, 3, 0, 2, 0, 1, 1, 1, 2, 3, 4, 4, 3, 2, 1, 1, 1, 0, 1, 0, 2, 0, 2, 0, 1, 0, 1, 1, 1, 4, 7, 11, 13, 13, 11, 7, 4, 1, 1, 1, 0, 1, 0, 3, 0, 4, 0, 3, 0, 1, 0, 1
Offset: 1

Views

Author

Andrew Howroyd, Sep 17 2018

Keywords

Examples

			Triangle begins, n >= 1, 0 <= k < n:
  1;
  1, 1;
  1, 0, 1;
  1, 1, 1, 1;
  1, 0, 1, 0,  1;
  1, 1, 2, 2,  1,  1;
  1, 0, 1, 0,  1,  0,  1;
  1, 1, 2, 3,  3,  2,  1,  1;
  1, 0, 2, 0,  3,  0,  2,  0,  1;
  1, 1, 2, 3,  4,  4,  3,  2,  1,  1;
  1, 0, 1, 0,  2,  0,  2,  0,  1,  0,  1;
  1, 1, 4, 7, 11, 13, 13, 11,  7,  4,  1,  1;
  1, 0, 1, 0,  3,  0,  4,  0,  3,  0,  1,  0,  1;
  1, 1, 2, 3,  6,  6,  9,  9,  6,  6,  3,  2,  1,  1;
  1, 0, 3, 0,  8,  0, 12,  0, 12,  0,  8,  0,  3,  0, 1;
  1, 1, 3, 7, 16, 27, 40, 48, 48, 40, 27, 16,  7,  3, 1, 1;
  1, 0, 1, 0,  4,  0,  7,  0, 10,  0,  7,  0,  4,  0, 1, 0, 1;
  1, 1, 4, 7, 16, 24, 38, 45, 54, 54, 45, 38, 24, 16, 7, 4, 1, 1;
  ...
		

Crossrefs

Columns k=2..12 (even n only for odd k) are A023645, A023646, A023647, A023640, A023641, A023642, A023643, A023644, A023637, A023638, A023639.
Row sums are A006799.

A185959 Number of Cayley graphs on n nodes.

Original entry on oeis.org

1, 2, 2, 4, 3, 8, 4, 14, 9, 20, 8, 74, 14, 56, 44, 278, 36, 376, 60, 1132, 240, 816, 188, 15394, 464, 4104, 1434, 25784, 1182, 45184, 2192, 659232, 6768, 131660, 11144, 1959040, 14602, 814216, 48462, 13055904, 52488, 9461984, 99880, 39134544, 399126, 34333800, 364724
Offset: 1

Views

Author

Eric W. Weisstein, Feb 07 2011

Keywords

Comments

First differs from A006799 at n = 10.

Crossrefs

Row sums of A319372.

Programs

Formula

a(n) = A006799(n) - A006792(n).

Extensions

a(32)-a(47) from Danny Rorabaugh, Nov 26 2018

A006792 Number of n-node vertex-transitive graphs which are not Cayley graphs.

Original entry on oeis.org

2, 0, 0, 0, 0, 4, 8, 0, 4, 0, 82, 0, 0, 0, 112, 0, 132, 0, 66, 0, 1124, 0, 18170, 0, 920, 6, 4162, 0, 0, 0, 48266, 0, 242, 0, 96, 294, 0, 0
Offset: 10

Views

Author

Keywords

References

  • McKay, Brendan D.; Royle, Gordon F.; The transitive graphs with at most 26 vertices. Ars Combin. 30 (1990), 161-176.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Formula

a(n) = A006799(n) - A185959(n). - Andrew Howroyd, Nov 27 2018

Extensions

More terms from Vladeta Jovovic, Jun 30 2007
a(32)-a(47) from Andrew Howroyd, Nov 27 2018
Duplicate a(32) removed by Andrew Howroyd, Sep 05 2019

A319368 Triangle read by rows: T(n,k) is the number of simple connected vertex transitive graphs with n nodes and valency k, (0 <= k < n).

Original entry on oeis.org

1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 2, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 2, 3, 2, 1, 1, 0, 0, 1, 0, 3, 0, 2, 0, 1, 0, 0, 1, 3, 3, 4, 3, 2, 1, 1, 0, 0, 1, 0, 2, 0, 2, 0, 1, 0, 1, 0, 0, 1, 4, 10, 12, 13, 11, 7, 4, 1, 1, 0, 0, 1, 0, 3, 0, 4, 0, 3, 0, 1, 0, 1
Offset: 1

Views

Author

Andrew Howroyd, Sep 17 2018

Keywords

Examples

			Triangle begins:
  1;
  0, 1;
  0, 0, 1;
  0, 0, 1, 1;
  0, 0, 1, 0,  1;
  0, 0, 1, 2,  1,  1;
  0, 0, 1, 0,  1,  0,  1;
  0, 0, 1, 2,  3,  2,  1,  1;
  0, 0, 1, 0,  3,  0,  2,  0,  1;
  0, 0, 1, 3,  3,  4,  3,  2,  1,  1;
  0, 0, 1, 0,  2,  0,  2,  0,  1,  0,  1;
  0, 0, 1, 4, 10, 12, 13, 11,  7,  4,  1,  1;
  0, 0, 1, 0,  3,  0,  4,  0,  3,  0,  1,  0,  1;
  0, 0, 1, 3,  5,  6,  8,  9,  6,  6,  3,  2,  1,  1;
  0, 0, 1, 0,  7,  0, 12,  0, 12,  0,  8,  0,  3,  0, 1;
  0, 0, 1, 4, 13, 25, 39, 47, 48, 40, 27, 16,  7,  3, 1, 1;
  0, 0, 1, 0,  4,  0,  7,  0, 10,  0,  7,  0,  4,  0, 1, 0, 1;
  0, 0, 1, 5, 12, 23, 36, 45, 53, 54, 45, 38, 24, 16, 7, 4, 1, 1;
  ...
		

Crossrefs

Row sums are A006800.
Cf. A319367.

Formula

T(n,k) = Sum_{d|n} moebius(n/d) * A319367(d,k).

A006800 Number of connected vertex-transitive graphs with n nodes.

Original entry on oeis.org

1, 1, 1, 2, 2, 5, 3, 10, 7, 18, 7, 64, 13, 51, 44, 272, 35, 365, 59, 1190, 235, 807, 187, 15422, 461, 4221, 1425, 25792, 1181, 46236, 2191, 677116, 6759, 132543, 11144, 1962756, 14601, 814155, 48447, 13102946, 52487, 9461929, 99879, 39133822, 399365, 34333611, 364723
Offset: 1

Views

Author

Keywords

References

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

Crossrefs

Row sums of A319368.

Programs

Formula

Moebius transform of A006799. - Andrew Howroyd, Sep 18 2018

Extensions

More terms from Vladeta Jovovic, Jun 30 2007
a(32)-a(47) from Andrew Howroyd, Nov 27 2018

A330697 Numbers k such that every vertex-transitive graph of order k is a Cayley-graph.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 17, 19, 21, 22, 23, 25, 27, 29, 31, 33, 37, 38, 39, 41, 43, 46, 47, 49, 53, 55, 59, 61, 62, 67, 69, 71, 73, 79, 83, 86, 87, 89, 93, 94, 95, 97, 101, 103, 107, 109, 113, 115, 118, 121, 123, 125, 127, 129, 131, 133, 134, 137, 139
Offset: 1

Views

Author

M. Farrokhi D. G., Dec 26 2019

Keywords

Comments

Numbers k for which A185959(k) = A006799(k).
Numbers k for which A006792(k) = 0.
In the Farrokhi reference, a Cayley number is a number k such that all vertex transitive graphs of order k are Cayley graphs.

Crossrefs

Programs

  • GAP
    # See M. Farrokhi Github repository for a GAP program.

A330698 Numbers k such that there exists a non-Cayley vertex-transitive graph of order k.

Original entry on oeis.org

10, 15, 16, 18, 20, 24, 26, 28, 30, 32, 34, 35, 36, 40, 42, 44, 45, 48, 50, 51, 52, 54, 56, 57, 58, 60, 63, 64, 65, 66, 68, 70, 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85, 88, 90, 91, 92, 96, 98, 99, 100, 102, 104, 105, 106, 108, 110, 111, 112, 114, 116, 117, 119, 120, 122, 124
Offset: 1

Views

Author

M. Farrokhi D. G., Dec 26 2019

Keywords

Comments

Numbers k for which A185959(k) < A006799(k).
Numbers k for which A006792(k) <> 0.
In the Farrokhi reference, a Cayley number is a number k such that all vertex transitive graphs of order k are Cayley graphs.

Crossrefs

A054917 Number of connected unlabeled vertex-transitive graphs with n nodes such that complement is also connected.

Original entry on oeis.org

1, 0, 0, 0, 1, 2, 2, 6, 5, 14, 6, 54, 12, 46, 40, 258, 34, 350, 58, 1166, 230, 798, 186, 15338, 458, 4206, 1416, 25734, 1180, 46164, 2190, 676830, 6750, 132506, 11138, 1962310, 14600, 814094, 48432, 13101722, 52486, 9461632, 99878, 39133004, 399310, 34333422, 364722
Offset: 1

Views

Author

N. J. A. Sloane, May 24 2000

Keywords

Crossrefs

Programs

Formula

a(n) = 2*A006800(n) - A006799(n).

Extensions

Missing a(1) inserted and a(32)-a(47) from Andrew Howroyd, Nov 27 2018

A327754 Number of connected Cayley graphs on n nodes.

Original entry on oeis.org

1, 1, 1, 2, 2, 5, 3, 10, 7, 16, 7, 64, 13, 51, 40, 264, 35, 361, 59, 1110, 235, 807, 187, 15310, 461, 4089, 1425, 25726, 1181, 45118, 2191
Offset: 1

Views

Author

M. Farrokhi D. G., Sep 24 2019

Keywords

Crossrefs

Showing 1-9 of 9 results.