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 A232071 #6 Jul 23 2025 06:51:41 %S A232071 46,520,6624,82996,1043172,13105012,164650280,2068621706,25989674166, %T A232071 326528021922,4102419848778,51541819920986,647559075731254, %U A232071 8135777066019200,102215953652767856,1284216749830662044 %N A232071 Number of (n+1)X(3+1) 0..1 arrays with every element equal to some horizontal, diagonal or antidiagonal neighbor, with top left element zero. %C A232071 Column 3 of A232076 %H A232071 R. H. Hardin, <a href="/A232071/b232071.txt">Table of n, a(n) for n = 1..210</a> %F A232071 Empirical: a(n) = 10*a(n-1) +33*a(n-2) +6*a(n-3) -176*a(n-4) -300*a(n-5) -15*a(n-6) -76*a(n-7) +79*a(n-8) +72*a(n-9) -16*a(n-10) %e A232071 Some solutions for n=4 %e A232071 ..0..1..1..1....0..1..1..1....0..0..1..0....0..0..0..0....0..0..1..1 %e A232071 ..1..0..1..1....1..0..0..0....1..1..0..1....0..1..0..0....0..1..1..1 %e A232071 ..0..0..0..1....0..1..1..1....1..0..1..1....1..1..0..0....1..1..0..0 %e A232071 ..0..1..1..0....0..1..0..0....1..1..1..0....1..1..0..0....0..1..1..1 %e A232071 ..1..1..0..1....1..0..0..0....1..1..0..0....1..0..0..0....0..0..0..1 %K A232071 nonn %O A232071 1,1 %A A232071 _R. H. Hardin_, Nov 17 2013