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 A266127 #6 Mar 09 2023 17:35:33 %S A266127 5,49,117,572,4336,19750,102201,620508,3041449,16217839,93738044, %T A266127 476322405,2546428711,14301936049,74467601183,398781566199, %U A266127 2199927226366,11619003130461,62319679692416,340185096129345,1811374715345253 %N A266127 Number of n X 4 integer arrays with each element equal to the number of horizontal, diagonal and antidiagonal neighbors exactly one smaller than itself. %C A266127 Column 4 of A266131. %H A266127 R. H. Hardin, <a href="/A266127/b266127.txt">Table of n, a(n) for n = 1..210</a> %e A266127 Some solutions for n=4 %e A266127 ..2..1..0..1....1..0..2..1....1..0..0..0....1..0..0..1....0..0..1..1 %e A266127 ..2..1..1..0....0..2..0..1....0..2..2..1....0..2..2..0....0..2..0..1 %e A266127 ..1..2..2..1....0..2..1..2....0..2..1..1....1..0..2..1....0..2..1..0 %e A266127 ..0..0..0..0....0..0..1..2....1..0..0..1....1..2..0..1....0..2..1..2 %Y A266127 Cf. A266131. %K A266127 nonn %O A266127 1,1 %A A266127 _R. H. Hardin_, Dec 21 2015