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Search: a006621 -id:a006621
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Zarankiewicz's problem k_4(n,n+1).
(Formerly M5071)
+10
12
19, 27, 37, 46, 56, 68, 80, 94, 109
OFFSET
4,1
COMMENTS
a(n) is the least k such that every n X (n+1) {0,1}-matrix with k ones contains an all ones 4 X 4 submatrix. - Sean A. Irvine, May 18 2017
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
R. K. Guy, A many-facetted problem of Zarankiewicz, Lect. Notes Math. 110 (1969), 129-148.
CROSSREFS
Cf. A006616 (k_4(n)), A006620 (k_2(n,n+1)), A006621 (k_3(n,n+1)).
KEYWORD
nonn,more
EXTENSIONS
a(9)-a(12) from Andrew Howroyd, Dec 26 2021
STATUS
approved
A variant of Zarankiewicz's problem: a(n) is the least k such that every n X (n+1) {0,1}-matrix with k ones contains an all-ones 2 X 2 submatrix.
(Formerly M3775)
+10
6
5, 8, 11, 15, 19, 23, 27, 32, 37, 43, 49, 54, 59, 64
OFFSET
2,1
COMMENTS
a(n) <= A205805(2*n+1) + 1. - Max Alekseyev, Feb 02 2024
REFERENCES
R. K. Guy, A many-facetted problem of Zarankiewicz, Lect. Notes Math. 110 (1969), 129-148.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
KEYWORD
nonn,more
EXTENSIONS
Name changed at the suggestion of Sean A. Irvine by Max Alekseyev, Feb 02 2024
STATUS
approved
A variant of Zarankiewicz's problem: a(n) is the least k such that every n X n {0,1}-matrix with k ones contains an all-ones 2 X 4 submatrix.
(Formerly M4925)
+10
4
14, 21, 26, 32, 41, 48, 56, 67
OFFSET
4,1
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
R. K. Guy, A problem of Zarankiewicz, Research Paper No. 12, Dept. of Math., Univ. Calgary, Jan. 1967. [Annotated and scanned copy, with permission]
R. K. Guy, A many-facetted problem of Zarankiewicz, Lect. Notes Math. 110 (1969), 129-148.
Dmitry I. Ignatov, When contranominal scales give a solution to the Zarankiewicz problem?, Workshop Notes, 12th Int'l Wksp. Formal Concept Analysis Artif. Intel. (FCA4AI 2024), 27-38. See p. 35.
KEYWORD
nonn,more
EXTENSIONS
Name updated at the suggestion of Sean A. Irvine by Max Alekseyev, Feb 02 2024
STATUS
approved
A variant of Zarankiewicz's problem: a(n) is the least k such that every n X n {0,1}-matrix with k ones contains an all-ones 3 X 4 submatrix.
(Formerly M4960)
+10
4
15, 22, 31, 38, 46, 57
OFFSET
4,1
REFERENCES
R. K. Guy, A many-facetted problem of Zarankiewicz, Lect. Notes Math. 110 (1969), 129-148.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
KEYWORD
nonn,more
EXTENSIONS
Name changed at the suggestion of Sean A. Irvine and a(9) added by Max Alekseyev, Feb 02 2024
STATUS
approved
A variant of Zarankiewicz's problem: a(n) is the least k such that every n X (n+1) {0,1}-matrix with k ones contains an all-ones 3 X 4 submatrix.
(Formerly M4826)
+10
4
12, 18, 26, 33, 41, 51
OFFSET
3,1
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
R. K. Guy, A problem of Zarankiewicz, Research Paper No. 12, Dept. of Math., Univ. Calgary, Jan. 1967. [Annotated and scanned copy, with permission]
R. K. Guy, A many-facetted problem of Zarankiewicz, Lect. Notes Math. 110 (1969), 129-148.
KEYWORD
nonn,more
EXTENSIONS
Name edited at the suggestion of Sean A. Irvine and a(8) added by Max Alekseyev, Feb 02 2024
STATUS
approved
A variant of Zarankiewicz's problem: a(n) is the least k such that every n X (n+2) {0,1}-matrix with k ones contains an all-ones 3 X 4 submatrix.
(Formerly M4926)
+10
4
14, 21, 28, 36, 45, 55
OFFSET
3,1
REFERENCES
R. K. Guy, A many-facetted problem of Zarankiewicz, Lect. Notes Math. 110 (1969), 129-148.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
KEYWORD
nonn,more
EXTENSIONS
Name changed at the suggestion of Sean A. Irvine and a(8) added by Max Alekseyev, Feb 02 2024
STATUS
approved

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