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 A219424 #5 Jul 23 2025 00:26:46 %S A219424 1,65,436,3617,28154,218838,1709703,13384389,104853209,820979848, %T A219424 6427053212,50316786006,393951173336,3084409493138,24148717621856, %U A219424 189066773722441,1480260894360447,11589420628440440 %N A219424 Unchanging value maps: number of 4Xn binary arrays indicating the locations of corresponding elements unequal to no horizontal or antidiagonal neighbor in a random 0..2 4Xn array. %C A219424 Row 4 of A219421 %e A219424 Some solutions for n=3 %e A219424 ..1..0..0....0..0..1....1..0..1....0..0..1....1..1..1....1..0..0....1..1..1 %e A219424 ..0..0..1....0..0..1....0..0..1....1..0..0....1..0..1....0..0..1....1..1..1 %e A219424 ..0..0..1....1..0..0....1..0..0....1..0..0....0..0..0....1..0..0....1..1..0 %e A219424 ..1..0..0....1..0..1....0..1..1....1..0..0....0..0..0....0..0..0....0..0..0 %K A219424 nonn %O A219424 1,2 %A A219424 _R. H. Hardin_ Nov 19 2012