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 A208164 #7 Jul 22 2025 21:12:47 %S A208164 2,4,4,6,16,6,9,36,36,9,13,81,102,81,14,19,169,281,287,196,21,28,361, %T A208164 699,981,882,441,31,41,784,1799,2920,3893,2491,961,46,60,1681,4706, %U A208164 9039,14446,13825,6759,2116,68,88,3600,12161,28681,55576,63031,46611,18528 %N A208164 T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 0 1 0 vertically. %C A208164 Table starts %C A208164 ..2....4.....6......9......13......19.......28........41.........60..........88 %C A208164 ..4...16....36.....81.....169.....361......784......1681.......3600........7744 %C A208164 ..6...36...102....281.....699....1799.....4706.....12161......31356.......81206 %C A208164 ..9...81...287....981....2920....9039....28681.....89623.....278652......872602 %C A208164 .14..196...882...3893...14446...55576...222487....873641....3397748....13352522 %C A208164 .21..441..2491..13825...63031..297702..1474641...7151473...34264481...166182659 %C A208164 .31..961..6759..46611..258952.1493661..9072707..53874293..315713411..1874906825 %C A208164 .46.2116.18528.159545.1088966.7719181.57903614.424153857.3061342878.22414028568 %H A208164 R. H. Hardin, <a href="/A208164/b208164.txt">Table of n, a(n) for n = 1..544</a> %e A208164 Some solutions for n=4 k=3 %e A208164 ..0..1..1....0..0..1....0..0..1....1..0..0....1..0..0....1..1..0....0..0..1 %e A208164 ..0..0..1....1..0..0....0..0..1....0..0..1....1..0..0....1..0..0....0..1..1 %e A208164 ..0..1..0....1..0..0....0..0..1....0..0..1....1..0..0....1..1..0....0..1..0 %e A208164 ..0..1..0....1..0..0....0..0..1....0..0..1....1..0..0....0..1..0....0..1..0 %Y A208164 Column 1 is A038718(n+2) %Y A208164 Column 2 is A207069 %Y A208164 Column 3 is A207237 %Y A208164 Row 1 is A000930(n+3) %Y A208164 Row 2 is A207170 %Y A208164 Row 3 is A207961 %K A208164 nonn,tabl %O A208164 1,1 %A A208164 _R. H. Hardin_ Feb 24 2012