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 A179594 #9 Oct 19 2019 04:16:18 %S A179594 2,20,1308,10199370,131487690152 %N A179594 Y-coordinate of the first n*n non-coprime block above the line x=y in the first quadrant. %C A179594 a(n) is the minimum y that satisfies x <= y and the GCD of (x,y),(x+1,y), ..., (x+n-1,y), (x,y+1),(x+1,y+1), ..., (x+n-1,y+1), ..., (x,y+n-1),(x+1,y+n-1), ..., (x+n-1,y+n-1) are all larger than 1. %D A179594 Stephen Wolfram, A New Kind of Science, Wolfram Media, 2002, p. 1093. %H A179594 The first 4 terms are found in Stephen Wolfram <a href="http://www.wolframscience.com/nksonline/toc.html">A New Kind of Science</a> %H A179594 The 5th term has been posted on <a href="http://bbs.emath.ac.cn/viewthread.php?tid=1948&page=4&fromuid=1394#pid24048">bbs.emath.ac.cn</a> %e A179594 a(2)=20 because the GCDs of (14,20), (15,20), (14,21), (15,21) are all larger than 1, and there is no such array within x <= y < 20. %K A179594 nonn,hard,more %O A179594 1,1 %A A179594 _Yi Yang_, Jul 20 2010