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 A188994 #7 Feb 21 2025 15:21:27 %S A188994 16,256,1793,10812,68064,423606,2613530,16035624,97883197,595766564, %T A188994 3617770796,21938495472,132905120076,804648760664,4869522949489, %U A188994 29461013798230,178208981945456,1077853513894740,6518619188201742 %N A188994 Number of 4 X n binary arrays without the pattern 0 0 1 antidiagonally or horizontally. %C A188994 Row 4 of A188992. %H A188994 R. H. Hardin, <a href="/A188994/b188994.txt">Table of n, a(n) for n = 1..200</a> %F A188994 Empirical: a(n) = 13*a(n-1) -24*a(n-2) -309*a(n-3) +1139*a(n-4) +2904*a(n-5) -15708*a(n-6) -13388*a(n-7) +114908*a(n-8) +27510*a(n-9) -517862*a(n-10) +10696*a(n-11) +1525375*a(n-12) -199987*a(n-13) -2999240*a(n-14) +537335*a(n-15) +3938119*a(n-16) -825688*a(n-17) -3403810*a(n-18) +826898*a(n-19) +1870596*a(n-20) -531896*a(n-21) -607828*a(n-22) +201144*a(n-23) +99904*a(n-24) -37536*a(n-25) -5568*a(n-26) +2304*a(n-27) for n>30. %e A188994 Some solutions for 4 X 3 %e A188994 ..1..1..1....1..0..0....1..0..0....0..1..0....0..1..0....1..0..1....1..0..1 %e A188994 ..1..1..1....1..0..1....0..1..0....0..1..1....1..1..0....1..1..0....1..0..0 %e A188994 ..1..1..0....0..1..1....1..1..1....1..1..0....1..1..0....1..1..0....1..0..1 %e A188994 ..1..0..1....0..0..0....1..1..1....1..1..0....1..0..0....1..0..0....0..1..1 %Y A188994 Cf. A188992. %K A188994 nonn %O A188994 1,1 %A A188994 _R. H. Hardin_, Apr 15 2011