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 1-2 of 2 results.

A115196 Triangle read by rows formed from nonzero entries in table of number of graphs on n nodes with clique number k.

Original entry on oeis.org

1, 1, 2, 1, 3, 6, 1, 4, 15, 13, 1, 5, 30, 82, 37, 1, 6, 51, 301, 578, 106, 1, 7, 80, 842, 4985, 6021, 409, 1, 8, 117, 1995, 27107, 142276, 101267, 1896, 1, 9, 164, 4210, 112225, 1724440, 7269487, 2882460, 12171
Offset: 2

Views

Author

N. J. A. Sloane, based on email from Keith Briggs, Apr 03 2006

Keywords

Examples

			Table: number of graphs on n nodes with clique number k
n = .1...2...3...4....5....6.....7......8........9.......10.
k ----------------------------------------------------------
2....0...1...2...6...13...37...106....409.....1896....12171 = A052450
3....0...0...1...3...15...82...578...6021...101267..2882460 = A052451
4....0...0...0...1...4....30...301...4985...142276..7269487 = A052452
5....0...0...0...0...1....5.....51....842....27107..1724440 = A077392
6....0...0...0...0...0....1......6.....80.....1995...112225 = A077393
7....0...0...0...0...0....0......1......7......117.....4210 = A077394
8....0...0...0...0...0....0......0......1........8......164 = A205577
9....0...0...0...0...0....0......0......0........1........9 = A205578
10...0...0...0...0...0....0......0......0........0........1.

Links

Crossrefs

Cf. A287024, A263341. Partial column sums: A304124, A304125.

Formula

1+Sum_{k>=2} T(n,k) = A000088(n). - R. J. Mathar, May 06 2018

A304124 Number of simple graphs with n vertices which contain no K4 subgraph.

Original entry on oeis.org

1, 2, 4, 10, 29, 120, 685, 6431, 103164, 2894632, 138892304, 11118977705, 1459412127955
Offset: 1

Views

Author

Brendan McKay, May 06 2018

Keywords

Comments

The graphs do not need to be connected.

Crossrefs

Cf. A000088, A006785 (no K3), A115196 (graphs by clique number), A304125 (no K5).

Formula

a(n) = 1+A052450(n)+A052451(n).

Extensions

a(13) from Brendan McKay, May 08 2018
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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