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 A229429 #7 Jul 23 2025 05:44:33 %S A229429 1,1,1,1,1,1,1,0,0,1,1,0,0,0,1,1,2,24,24,2,1,1,14,1660,12072,1660,14, %T A229429 1,1,90,160524,16595940,16595940,160524,90,1,1,646,21914632, %U A229429 46053512896,696497375736,46053512896,21914632,646,1 %N A229429 Number of ways to label the cells of an m-by-n grid such that no (orthogonally) adjacent cells have adjacent labels; square array A(m,n) read by antidiagonals. %e A229429 The A(2,3) = 24 valid labelings of a 2-by-3 grid are %e A229429 153 163 135 513 415 416 %e A229429 426 425 462 246 263 253 %e A229429 together with their 18 reflections and rotations. %e A229429 The square array starts: %e A229429 1, 1, 1, 1, 1, 1, ... %e A229429 1, 1, 0, 0, 2, ... %e A229429 1, 0, 0, 24, ... %e A229429 1, 0, 24, ... %e A229429 1, 2, ... %e A229429 1, ... %Y A229429 A(1, n) = A002464(n), A(2, n) = A229430(n) %K A229429 nonn,tabl %O A229429 0,17 %A A229429 _Jens Voß_, Sep 23 2013