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 A194505 #8 Jul 22 2025 12:34:25 %S A194505 1,2,1,3,8,4,4,27,72,2,5,64,776,1020,1,6,125,4160,59052,32768,1,7,216, %T A194505 15804,1048560,14348907,2097152,1,8,343,46872,9765630,1073741824, %U A194505 10460353203,268460064,16,9,512,118096,60466140,30517578125 %N A194505 T(n,k)=Number of lower triangles of an n X n 0..k array with each element unequal to the sum mod k+1 of its horizontal and vertical neighbors. %C A194505 Table starts %C A194505 .1.........2..............3.................4....................5 %C A194505 .1.........8.............27................64..................125 %C A194505 .4........72............776..............4160................15804 %C A194505 .2......1020..........59052...........1048560..............9765630 %C A194505 .1.....32768.......14348907........1073741824..........30517578125 %C A194505 .1...2097152....10460353203.....4398046511104......476837158203125 %C A194505 .1.268460064.22876792454961.72057594037927936.37252902986083985625 %H A194505 R. H. Hardin, <a href="/A194505/b194505.txt">Table of n, a(n) for n = 1..62</a> %e A194505 Some solutions for n=4 k=3 %e A194505 ..3........0........1........1........1........2........2........0 %e A194505 ..2.1......1.1......3.2......3.3......3.2......3.0......3.0......1.2 %e A194505 ..1.2.1....2.3.2....1.1.2....2.3.1....2.1.1....2.3.1....3.0.1....0.3.1 %e A194505 ..2.0.1.3..0.0.0.3..0.1.3.1..1.2.1.0..0.3.3.0..3.3.0.1..1.3.0.3..2.3.3.1 %Y A194505 Column 1 is A144260(n+1) %K A194505 nonn,tabl %O A194505 1,2 %A A194505 _R. H. Hardin_ Aug 27 2011