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 A218899 #8 Jul 24 2025 19:40:02 %S A218899 8,16,72,212,786,2594,9110,31062,107510,369596,1274760,4390640, %T A218899 15132044,52139518,179669784,619118588,2133406676,7351495186, %U A218899 25332356634,87292564824,300799972600,1036523262982,3571740490936,12307815695422 %N A218899 Number of 3Xn arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random 0..1 3Xn array. %C A218899 Row 3 of A218897 %H A218899 R. H. Hardin, <a href="/A218899/b218899.txt">Table of n, a(n) for n = 1..210</a> %F A218899 Empirical: a(n) = 2*a(n-1) +7*a(n-2) -4*a(n-3) -6*a(n-4) -10*a(n-5) -20*a(n-6) +15*a(n-7) -a(n-8) +22*a(n-9) +14*a(n-10) -5*a(n-11) -6*a(n-13) -2*a(n-14) %e A218899 Some solutions for n=3 %e A218899 ..0..0..0....0..0..0....1..0..0....1..0..0....1..0..0....0..0..1....1..0..1 %e A218899 ..0..0..0....1..0..1....1..0..0....0..0..0....1..0..0....0..0..1....0..0..1 %e A218899 ..0..0..0....0..0..1....0..0..0....0..0..0....0..0..1....0..0..0....1..0..0 %K A218899 nonn %O A218899 1,1 %A A218899 _R. H. Hardin_ Nov 08 2012