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.

A350292 Triangle read by rows: the n-th row gives the saturated vertex Turán numbers for the cube graph Q_n.

Original entry on oeis.org

1, 2, 1, 6, 3, 1, 12, 8, 4, 1, 24, 20, 10, 5, 1
Offset: 1

Views

Author

Stefano Spezia, Dec 23 2021

Keywords

Comments

The k-th saturated vertex Turán number for the cube graph Q_n is the maximum number of vertices to be deleted from the cube graph such that no subgraph Q_k is complete and each of the deleted vertices being added again completes a subgraph Q_k (see Harborth and Nienborg).

Examples

			n\k |   1    2    3    4    5
----+------------------------
  1 |   1
  2 |   2    1
  3 |   6    3    1
  4 |  12    8    4    1
  5 |  24   20   10    5    1
  ...
		

Crossrefs

Cf. A350293 (k = 1), A350295 (2nd subdiagonal).

Formula

T(n, n) = 1 and T(n, n-1) = n (see Theorem 2 in Harborth and Nienborg).

A350294 a(n) = floor(n*2^n/(n + 1)).

Original entry on oeis.org

0, 1, 2, 6, 12, 26, 54, 112, 227, 460, 930, 1877, 3780, 7606, 15291, 30720, 61680, 123790, 248346, 498073, 998643, 2001826, 4011942, 8039082, 16106127, 32263876, 64623350, 129424237, 259179060, 518975214, 1039104990, 2080374784, 4164816771, 8337289456, 16689015778
Offset: 0

Views

Author

Stefano Spezia, Dec 23 2021

Keywords

Crossrefs

Programs

  • Maple
    f:= n -> floor(n*2^n/(n+1)):
    map(f, [$0..40]); # Robert Israel, Dec 27 2021
  • Mathematica
    Table[Floor[n 2^n/(n+1)],{n,0,34}]

Formula

A350293(n) <= a(n) (see Lemma 1 in Harborth and Nienborg).
a(n) ~ 2^n.
Showing 1-2 of 2 results.