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 A299595 #4 Feb 13 2018 21:01:35 %S A299595 1,2,2,3,1,3,5,3,3,5,8,5,5,5,8,13,8,11,11,8,13,21,15,19,23,19,15,21, %T A299595 34,26,35,53,53,35,26,34,55,45,65,121,113,121,65,45,55,89,80,120,250, %U A299595 256,256,250,120,80,89,144,140,220,533,541,576,541,533,220,140,144,233,245 %N A299595 T(n,k)=Number of nXk 0..1 arrays with every element unequal to 0, 1 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. %C A299595 Table starts %C A299595 ..1..2...3....5....8...13....21....34....55.....89....144....233.....377 %C A299595 ..2..1...3....5....8...15....26....45....80....140....245....431.....756 %C A299595 ..3..3...5...11...19...35....65...120...220....404....744...1369....2517 %C A299595 ..5..5..11...23...53..121...250...533..1162...2490...5327..11465...24641 %C A299595 ..8..8..19...53..113..256...541..1148..2488...5349..11453..24617...52916 %C A299595 .13.15..35..121..256..576..1225..2601..5625..12100..25921..55696..119716 %C A299595 .21.26..65..250..541.1225..2583..5488.11899..25570..54750.117697..252985 %C A299595 .34.45.120..533.1148.2601..5488.11656.25269..54309.116285.249968..537305 %C A299595 .55.80.220.1162.2488.5625.11899.25269.54738.117679.252010.541648.1164265 %H A299595 R. H. Hardin, <a href="/A299595/b299595.txt">Table of n, a(n) for n = 1..9934</a> %F A299595 Empirical for diagonal: [linear recurrence of order 15] for n>18 %F A299595 Empirical for column k: %F A299595 k=1: a(n) = a(n-1) +a(n-2) %F A299595 k=2: a(n) = a(n-1) +2*a(n-3) +a(n-5) for n>6 %F A299595 k=3: a(n) = a(n-1) +2*a(n-3) +a(n-4) +a(n-5) for n>8 %F A299595 k=4..99: a(n) = a(n-1) +a(n-2) +3*a(n-3) +a(n-4) -a(n-5) -a(n-6) for n>9 %e A299595 Some solutions for n=5 k=4 %e A299595 ..0..0..1..0. .0..1..0..0. .0..1..0..0. .0..0..0..0. .0..0..0..0 %e A299595 ..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..1. .1..0..0..0 %e A299595 ..0..0..0..0. .0..0..0..0. .0..0..0..1. .0..0..0..0. .0..0..0..0 %e A299595 ..1..0..0..1. .1..0..0..0. .1..0..0..0. .1..0..0..0. .0..0..0..1 %e A299595 ..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..0. .0..0..0..0 %Y A299595 Column 1 is A000045(n+1). %Y A299595 Column 2 is A193147. %K A299595 nonn,tabl %O A299595 1,2 %A A299595 _R. H. Hardin_, Feb 13 2018