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 A208369 #7 Jul 22 2025 21:18:11 %S A208369 2,4,4,6,16,6,10,36,36,9,16,100,114,81,14,26,256,450,351,196,21,42, %T A208369 676,1644,1953,1162,441,31,68,1764,6186,9999,9338,3633,961,46,110, %U A208369 4624,23010,52821,67396,41433,11067,2116,68,178,12100,85992,275769,507682,422541 %N A208369 T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 0 vertically. %C A208369 Table starts %C A208369 ..2....4.....6.....10.......16........26.........42...........68...........110 %C A208369 ..4...16....36....100......256.......676.......1764.........4624.........12100 %C A208369 ..6...36...114....450.....1644......6186......23010........85992........320742 %C A208369 ..9...81...351...1953.....9999.....52821.....275769......1446381.......7572429 %C A208369 .14..196..1162...9338....67396....507682....3759574.....28035840.....208473118 %C A208369 .21..441..3633..41433...422541...4503765...47178453....497691495....5235328875 %C A208369 .31..961.11067.177909..2563359..38542393..570085195...8487780687..126039261499 %C A208369 .46.2116.33994.774134.15730896.334331082.6982331490.146860432968.3080068967794 %H A208369 R. H. Hardin, <a href="/A208369/b208369.txt">Table of n, a(n) for n = 1..760</a> %e A208369 Some solutions for n=4 k=3 %e A208369 ..0..1..1....1..1..1....1..1..1....0..1..0....0..1..0....0..1..0....1..1..0 %e A208369 ..0..1..1....1..0..1....1..1..1....1..1..1....1..0..1....0..1..0....1..1..0 %e A208369 ..0..1..1....1..1..1....1..1..0....1..1..1....1..0..1....0..1..0....1..0..0 %e A208369 ..0..1..1....0..1..1....1..0..1....1..1..1....1..0..1....0..1..0....1..0..0 %Y A208369 Column 1 is A038718(n+2) %Y A208369 Column 2 is A207069 %Y A208369 Column 3 is A207421 %Y A208369 Row 1 is A006355(n+2) %Y A208369 Row 2 is A206981 %Y A208369 Row 3 is A207718 %K A208369 nonn,tabl %O A208369 1,1 %A A208369 _R. H. Hardin_ Feb 25 2012