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.
%I A006626 M5071 #18 Dec 26 2021 18:26:15
%S A006626 19,27,37,46,56,68,80,94,109
%N A006626 Zarankiewicz's problem k_4(n,n+1).
%C A006626 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
%D A006626 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A006626 R. K. Guy, <a href="http://dx.doi.org/10.1007/BFb0060112">A many-facetted problem of Zarankiewicz</a>, Lect. Notes Math. 110 (1969), 129-148.
%Y A006626 Cf. A006616 (k_4(n)), A006620 (k_2(n,n+1)), A006621 (k_3(n,n+1)).
%K A006626 nonn,more
%O A006626 4,1
%A A006626 _N. J. A. Sloane_
%E A006626 a(9)-a(12) from _Andrew Howroyd_, Dec 26 2021