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 A350237 #27 Oct 31 2022 09:33:23 %S A350237 0,0,1,3,5,10,16,22,32,40,52,64,77,91,105,128 %N A350237 Minimum number of 1's in an n X n binary matrix with no zero 3 X 3 submatrix. %C A350237 The submatrix's rows and columns need not be contiguous, so the following matrix does not show a(4) = 1: %C A350237 .... %C A350237 .1.. %C A350237 .... %C A350237 .... %H A350237 Jeremy Tan, <a href="https://gist.github.com/Parcly-Taxel/705747d9b62b29967647eb680ca4cdd4">Python program with illustration of initial terms</a> %H A350237 Jeremy Tan, <a href="https://puzzling.stackexchange.com/q/114135">Two genies and their kind of chess</a>, Puzzling Stack Exchange, Dec 19 2021. (shows a(8) = 22) %H A350237 Jeremy Tan, <a href="https://math.stackexchange.com/q/4335395">What's the minimum number of people required?</a>, Mathematics Stack Exchange, Dec 20 2021. %H A350237 Jeremy Tan, <a href="https://arxiv.org/abs/2203.02283">An attack on Zarankiewicz's problem through SAT solving</a>, arXiv:2203.02283 [math.CO], 2022. %F A350237 a(n) = A347473(n) + 1 = n^2 - A001198(n) + 1. %F A350237 a(n) = n^2 - A350304(n). - _Max Alekseyev_, Oct 31 2022 %e A350237 a(4) = 3 because the following 4 X 4 binary matrix with 3 1's has no zero 3 X 3 submatrix, and all such matrices with fewer 1's have at least one zero 3 X 3 submatrix: %e A350237 1... %e A350237 .1.. %e A350237 ..1. %e A350237 .... %Y A350237 Column 3 of A339635. %Y A350237 Cf. A001198, A347473, A350304. %K A350237 nonn,hard,more %O A350237 1,4 %A A350237 _Jeremy Tan_, Dec 21 2021 %E A350237 a(12)-a(13) from _Andrew Howroyd_, Dec 23 2021 %E A350237 a(14)-a(15) from _Jeremy Tan_, Jan 03 2022 %E A350237 a(16) from _Jeremy Tan_, added by _Max Alekseyev_, Oct 31 2022