A006620 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)

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).

Links

Table of n, a(n) for n=2..15.

Crossrefs

Cf. A006613, A006614, A006615, A006616, A006617, A006618, A006619, A006621, A006622, A006623, A006624, A006625, A006626.

Cf. A001197, A072567, A191965, A191873, A001198, A205805, A347473, A347474, A350304, A350237.

Sequence in context: A363889 A118520 A001954 * A176628 A314390 A314391

Adjacent sequences: A006617 A006618 A006619 * A006621 A006622 A006623

Keyword

nonn,more

Author

N. J. A. Sloane

Extensions

Name changed at the suggestion of Sean A. Irvine by Max Alekseyev, Feb 02 2024

Status

approved