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 A116542 #6 Feb 05 2014 20:18:17 %S A116542 1,2,2,6,8,6,12,16,16,12,72,432,2016,432,72,72,2784,23904,23904,2784, %T A116542 72,864,35712,7102656,19611648,7102656,35712,864 %N A116542 Table B(m,n), read by antidiagonals, where B(m,n) is the number of ways integers 1,..,m*n can be put into an m X n grid so that every adjacent (NESW) pair of integers are coprime. %C A116542 Sequence suggested by _Leroy Quet_ on the SeqFan mailing list. B(1,n)=B(n,1)=A076220(n). %e A116542 The 16 configuration 3x2 are the following %e A116542 ------------------------------------------------ %e A116542 1 2 3 | 2 5 6 | 3 4 1 | 4 5 6 | 6 1 2 | 6 5 4 %e A116542 6 5 4 | 3 4 1 | 2 5 6 | 3 2 1 | 5 4 3 | 1 2 3 %e A116542 ------------------------------------------------ %e A116542 1 4 3 | 3 2 1 | 3 4 5 | 5 2 3 | 6 1 4 %e A116542 6 5 2 | 4 5 6 | 2 1 6 | 6 1 4 | 5 2 3 %e A116542 ------------------------------------------------ %e A116542 2 1 6 | 3 2 5 | 4 1 6 | 5 4 3 | 6 5 2 %e A116542 3 4 5 | 4 1 6 | 3 2 5 | 6 1 2 | 1 4 3 %e A116542 ------------------------------------------------ %Y A116542 Cf. A076220. %K A116542 nonn,tabl %O A116542 1,2 %A A116542 _Giovanni Resta_, Mar 28 2006