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 1-5 of 5 results.

A185244 Number of disconnected 4-regular simple graphs on n vertices with girth at least 4.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 2, 2, 15, 35, 247, 1692, 17409, 197924, 2492824, 33117880, 461597957, 6709514218, 101153412903, 1597440868898
Offset: 0

Views

Author

Jason Kimberley, Feb 22 2011

Keywords

Links

Crossrefs

4-regular simple graphs with girth at least 4: A033886 (connected), this sequence (disconnected), A185344 (not necessarily connected).
Disconnected 4-regular simple graphs with girth at least g: A033483 (g=3), this sequence (g=4), A185245 (g=5), A185246 (g=6).
Disconnected k-regular simple graphs with girth at least 4: A185214 (any k), A185204 (triangle); specified degree k: A185224 (k=2), A185234 (k=3), this sequence (k=4), A185254 (k=5), A185264 (k=6), A185274 (k=7), A185284 (k=8), A185294 (k=9).

Formula

a(n) = A185344(n) - A033886(n) = Euler_transformation(A033886)(n) - A033886(n).
a(n) = A185044(n) + A185245(n).

Extensions

a(31) appended by the author once A033886(23) was known, Nov 03 2011
a(31) corrected by the author, Jan 05 2013

A184944 Number of connected 4-regular simple graphs on n vertices with girth exactly 4.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 2, 2, 12, 31, 220, 1606, 16828, 193900, 2452818, 32670329, 456028472, 6636066091, 100135577616, 1582718909051
Offset: 0

Views

Author

Jason Kimberley, Jan 26 2011

Keywords

Examples

			a(0)=0 because even though the null graph (on zero vertices) is vacuously 4-regular and connected, since it is acyclic, it has infinite girth.
The a(8)=1 graph is the complete bipartite graph K_{4,4}.

Links

Crossrefs

4-regular simple graphs with girth exactly 4: this sequence (connected), A185044 (disconnected), A185144 (not necessarily connected).
Connected k-regular simple graphs with girth exactly 4: A006924 (k=3), this sequence (k=4), A184954 (k=5), A184964 (k=6), A184974 (k=7).
Connected 4-regular simple graphs with girth at least g: A006820 (g=3), A033886 (g=4), A058343 (g=5), A058348 (g=6).
Connected 4-regular simple graphs with girth exactly g: A184943 (g=3), this sequence (g=4), A184945 (g=5).

Formula

a(n) = A033886(n) - A058343(n).

Extensions

a(23) was appended by the author once A033886(23) was known, Nov 03 2011

A185144 Number of not necessarily connected 4-regular simple graphs on n vertices with girth exactly 4.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 2, 2, 12, 31, 220, 1606, 16829, 193900, 2452820, 32670331, 456028487, 6636066126, 100135577863, 1582718910743
Offset: 0

Views

Author

Jason Kimberley, Nov 04 2011

Keywords

Links

Crossrefs

Not necessarily connected k-regular simple graphs girth exactly 4: A198314 (any k), A185644 (triangle); fixed k: A026797 (k=2), A185134 (k=3), this sequence (k=4).
A185143 (g=3), A185144 (g=4).
Not necessarily connected 4-regular simple graphs with girth exactly g: A185140 (triangle); fixed g: A185143 (g=3), this sequence (g=4).

Formula

a(n) = A184944(n) + A185044(n) = A185140(n,4).

Extensions

Corrected by Jason Kimberley, Jan 03 2013

A185043 Number of disconnected 4-regular simple graphs on n vertices with girth exactly 3.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 3, 8, 25, 88, 377, 2026, 13349, 104593, 930571, 9124627, 96699740, 1095467916, 13175254799, 167460501260, 2241576473025, 31510509517563, 464047467911837, 7143984462730072, 114749034352969037, 1919656978492976231
Offset: 0

Views

Author

Jason Kimberley, Feb 29 2012

Keywords

Links

Crossrefs

4-regular simple graphs with girth exactly 3: A184943 (connected), this sequence (disconnected), A185143 (not necessarily connected).
Disconnected k-regular simple graphs with girth exactly 3: A210713 (any k), A210703 (triangle); for fixed k: A185033 (k=3), this sequence (k=4), A185053 (k=5), A185063 (k=6).
Disconnected 4-regular simple graphs with girth exactly g: this sequence (g=3), A185044 (g=4).

Formula

a(n) = A033483(n) - A185244(n).

Extensions

Terms a(27)-a(31), due to the extension of A006820 by Andrew Howroyd, from Jason Kimberley, Mar 16 2020

A185034 Number of disconnected 3-regular simple graphs on 2n vertices with girth exactly 4.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 2, 9, 35, 176, 1151, 10329, 120456, 1701834, 27500216, 492269472, 9599036308, 201954501535, 4555108534562
Offset: 0

Views

Author

Jason Kimberley, Feb 29 2012

Keywords

Links

Crossrefs

Disconnected k-regular simple graphs with girth exactly 4: this sequence (k=3), A185044 (k=4).
Disconnected 3-regular simple graphs with girth exactly g: A185033 (g=3), this sequence (g=4), A185035 (g=5), A185036 (g=6), A185037 (g=7).

Formula

a(n) = A185234(n) - A185235(n).
Showing 1-5 of 5 results.

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