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 A234121 #7 Jun 02 2025 09:12:15 %S A234121 313537,93113761,26937444801,7888454356625,2315408571668225, %T A234121 680845368964238145,200376051988817866625,58999673293833047076529, %U A234121 17376516489941449765539393,5118401705337856988983612385 %N A234121 Number of (n+1)X(7+1) 0..2 arrays with every 2X2 subblock having the absolute values of all six edge and diagonal differences no larger than 1. %C A234121 Column 7 of A234122 %H A234121 R. H. Hardin, <a href="/A234121/b234121.txt">Table of n, a(n) for n = 1..210</a> %H A234121 R. H. Hardin, <a href="/A234121/a234121.txt">Empirical recurrence of order 62</a> %F A234121 Empirical recurrence of order 62 (see link above) %e A234121 Some solutions for n=1 %e A234121 ..1..1..0..1..1..2..1..1....1..0..0..1..1..1..1..0....0..0..0..0..0..0..1..0 %e A234121 ..0..1..1..1..2..1..2..1....0..1..1..1..2..1..1..0....0..1..1..0..1..1..1..1 %K A234121 nonn %O A234121 1,1 %A A234121 _R. H. Hardin_, Dec 19 2013