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 A220579 #6 Jul 23 2025 01:14:48 %S A220579 1,2,1,4,8,1,8,21,32,1,16,115,91,128,1,32,371,1441,375,512,1,64,1504, %T A220579 8334,17505,1487,2048,1,128,5240,64497,165130,205323,5835,8192,1,256, %U A220579 19904,436288,2652007,3162375,2352642,22775,32768,1,512,71787,3036588 %N A220579 T(n,k)=Equals one maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly one of their horizontal and antidiagonal neighbors in a random 0..1 nXk array. %C A220579 Table starts %C A220579 .1.......2.......4..........8..........16...........32...........64.........128 %C A220579 .1.......8......21........115.........371.........1504.........5240.......19904 %C A220579 .1......32......91.......1441........8334........64497.......436288.....3036588 %C A220579 .1.....128.....375......17505......165130......2652007.....33180533...450926562 %C A220579 .1.....512....1487.....205323.....3162375....106841503...2449921734.65126683335 %C A220579 .1....2048....5835....2352642....59690533...4239598056.178051989526 %C A220579 .1....8192...22775...26616961..1120269376.166807007000 %C A220579 .1...32768...88683..299065708.20961430054 %C A220579 .1..131072..344975.3347252663 %C A220579 .1..524288.1341395 %C A220579 .1.2097152 %C A220579 .1 %H A220579 R. H. Hardin, <a href="/A220579/b220579.txt">Table of n, a(n) for n = 1..82</a> %e A220579 Some solutions for n=3 k=4 %e A220579 ..1..1..0..0....0..1..1..1....0..0..0..1....0..0..1..1....1..0..0..1 %e A220579 ..0..1..1..1....1..0..0..1....0..0..0..1....1..0..1..0....0..0..0..1 %e A220579 ..1..1..0..1....1..0..0..1....1..0..1..1....0..1..0..0....1..1..1..1 %Y A220579 Column 2 is A004171(n-1) %Y A220579 Row 1 is A000079(n-1) %K A220579 nonn,tabl %O A220579 1,2 %A A220579 _R. H. Hardin_ Dec 16 2012