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 A232961 #6 Jul 23 2025 07:46:26 %S A232961 4096,352947,85202361,18193384251,4082986991091,913176469752921, %T A232961 205030957086979647,46049854148275821783,10347651822185274889503, %U A232961 2325450833294278864661895,522642603826819656267942471 %N A232961 Number of 7Xn 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero. %C A232961 Row 7 of A232955 %H A232961 R. H. Hardin, <a href="/A232961/b232961.txt">Table of n, a(n) for n = 1..210</a> %e A232961 Some solutions for n=2 %e A232961 ..0..0....0..2....0..2....0..2....0..2....0..2....0..2....0..0....0..2....0..0 %e A232961 ..2..2....0..2....0..0....0..2....0..2....0..2....0..0....0..0....0..2....0..0 %e A232961 ..3..2....2..0....1..0....0..2....2..2....3..2....1..0....0..2....2..2....0..1 %e A232961 ..3..3....0..0....2..0....0..2....3..2....0..2....2..3....3..1....0..0....1..1 %e A232961 ..2..3....0..2....1..3....0..1....0..2....3..2....1..0....0..1....0..0....3..3 %e A232961 ..3..3....3..2....3..1....3..1....0..2....3..2....2..0....0..2....0..0....3..1 %e A232961 ..2..2....3..2....3..3....1..3....3..1....3..3....0..0....2..2....0..0....0..1 %K A232961 nonn %O A232961 1,1 %A A232961 _R. H. Hardin_, Dec 02 2013