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 1-3 of 3 results.

A006799 Number of vertex-transitive graphs with n nodes.

Original entry on oeis.org

1, 2, 2, 4, 3, 8, 4, 14, 9, 22, 8, 74, 14, 56, 48, 286, 36, 380, 60, 1214, 240, 816, 188, 15506, 464, 4236, 1434, 25850, 1182, 46308, 2192, 677402, 6768, 132580, 11150, 1963202, 14602, 814216, 48462, 13104170, 52488, 9462226, 99880, 39134640, 399420, 34333800, 364724
Offset: 1

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Author

Keywords

References

  • CRC Handbook of Combinatorial Designs, 1996, p. 649.
  • Brendan 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 A319367.

Formula

Inverse Moebius transform of A006800. - Andrew Howroyd, Sep 18 2018

Extensions

More terms from Vladeta Jovovic, Jun 30 2007
a(32)-a(47) from Danny Rorabaugh, Nov 26 2018

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).

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
Showing 1-3 of 3 results.