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.

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A155934 The sequence {k(m)} defined in A005991.

Original entry on oeis.org

2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
Offset: 2

Views

Author

N. J. A. Sloane, Aug 15 2010

Keywords

Comments

All known terms (n=2 to n=43) agree with A368941(n). - Eric W. Weisstein, Apr 16 2019 and Jan 10 2024

Links

Crossrefs

Cf. A003509, A005991, A368941.

Formula

n^(1/2) - n^(5/16) < a(n) <= floor((1/2) * (3 + sqrt(4*n-3))) [from Wang and Guy]. - Sean A. Irvine, Jun 06 2015

A003509 Let k(m) denote the least integer such that every m X m (0,1)-matrix with exactly k(m) ones in each row and in each column contains a 2 X 2 submatrix without zeros. The sequence gives the index n of the first term in each string of equal entries in the {k(m)} sequence (see A155934).

Original entry on oeis.org

2, 3, 7, 13, 21, 31
Offset: 2

Views

Author

N. J. A. Sloane

Keywords

References

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

Links

Crossrefs

Cf. A005991 (index of last term), A155934.

Extensions

Title made more specific by Sean A. Irvine, Jun 04 2015
Showing 1-2 of 2 results.

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

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