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 A217960 #6 Jul 22 2025 23:44:13 %S A217960 17,321,5415,93765,1602741,27317977,465184959,7919256577,134805742899, %T A217960 2294680520773,39060078023831,664879775228995,11317562137329901, %U A217960 192647146079979077,3279232808653682467,55818982418231563527 %N A217960 Number of nX4 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..2 nX4 array. %C A217960 Column 4 of A217964 %H A217960 R. H. Hardin, <a href="/A217960/b217960.txt">Table of n, a(n) for n = 1..38</a> %F A217960 Empirical: a(n) = 19*a(n-1) -23*a(n-2) -144*a(n-3) -675*a(n-4) +378*a(n-5) +3291*a(n-6) +4937*a(n-7) -1247*a(n-8) -12054*a(n-9) -12369*a(n-10) -5436*a(n-11) -816*a(n-12) +744*a(n-13) +364*a(n-14) +100*a(n-15) for n>16 %e A217960 Some solutions for n=3 %e A217960 ..1..0..2..2....0..0..1..1....0..0..2..1....0..0..0..2....1..1..1..2 %e A217960 ..0..0..0..0....2..1..0..2....2..1..1..1....0..1..1..2....1..2..1..1 %e A217960 ..2..2..0..0....0..0..0..2....2..1..1..2....1..2..2..2....1..1..1..1 %K A217960 nonn %O A217960 1,1 %A A217960 _R. H. Hardin_ Oct 16 2012