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 A297682 #4 Jan 03 2018 09:29:31 %S A297682 2,4,4,7,11,8,13,29,33,16,24,80,150,98,32,44,219,629,742,291,64,81, %T A297682 597,2790,4633,3744,865,128,149,1632,12110,32911,34872,18840,2570,256, %U A297682 274,4459,52889,221420,401678,260924,94891,7637,512,504,12181,230406,1519630 %N A297682 T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 1 or 4 neighboring 1s. %C A297682 Table starts %C A297682 ...2.....4.......7........13.........24...........44.............81 %C A297682 ...4....11......29........80........219..........597...........1632 %C A297682 ...8....33.....150.......629.......2790........12110..........52889 %C A297682 ..16....98.....742......4633......32911.......221420........1519630 %C A297682 ..32...291....3744.....34872.....401678......4202440.......45865837 %C A297682 ..64...865...18840....260924....4870764.....78957968.....1368968852 %C A297682 .128..2570...94891...1955750...59210634...1487819051....41030621948 %C A297682 .256..7637..477850..14651847..719647644..28013761161..1229127412701 %C A297682 .512.22693.2406649.109783269.8748946600.527589764007.36837288191422 %H A297682 R. H. Hardin, <a href="/A297682/b297682.txt">Table of n, a(n) for n = 1..287</a> %F A297682 Empirical for column k: %F A297682 k=1: a(n) = 2*a(n-1) %F A297682 k=2: a(n) = 2*a(n-1) +3*a(n-2) -a(n-4) %F A297682 k=3: a(n) = 5*a(n-1) -a(n-2) +8*a(n-3) -5*a(n-4) -30*a(n-5) +17*a(n-6) %F A297682 k=4: [order 16] %F A297682 k=5: [order 30] %F A297682 k=6: [order 57] %F A297682 Empirical for row n: %F A297682 n=1: a(n) = a(n-1) +a(n-2) +a(n-3) %F A297682 n=2: a(n) = a(n-1) +3*a(n-2) +4*a(n-3) +2*a(n-4) %F A297682 n=3: [order 8] %F A297682 n=4: [order 17] %F A297682 n=5: [order 41] %e A297682 Some solutions for n=4 k=4 %e A297682 ..0..1..0..1. .1..1..0..0. .0..0..0..1. .0..0..0..1. .0..0..0..0 %e A297682 ..0..0..1..1. .0..0..0..1. .1..0..1..0. .1..0..0..1. .1..0..0..0 %e A297682 ..0..1..0..0. .0..0..1..0. .1..0..0..0. .1..0..0..1. .0..0..0..0 %e A297682 ..0..1..0..0. .1..0..1..0. .0..1..0..0. .0..0..0..0. .0..0..1..1 %Y A297682 Column 1 is A000079. %Y A297682 Column 2 is A282990. %Y A297682 Row 1 is A000073(n+3). %Y A297682 Row 2 is A124861(n+1). %K A297682 nonn,tabl %O A297682 1,1 %A A297682 _R. H. Hardin_, Jan 03 2018