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 A221450 #6 Jul 23 2025 01:56:52 %S A221450 1,355,9829,230845,6415089,177320895,4832005625,131942833529, %T A221450 3606055280657,98529266203659,2692051448713949,73554857285973785, %U A221450 2009736562063323785,54911874439751493035,1500353181134236949205 %N A221450 Hilltop maps: number of 5Xn binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..1 5Xn array. %C A221450 Row 5 of A221446 %H A221450 R. H. Hardin, <a href="/A221450/b221450.txt">Table of n, a(n) for n = 1..49</a> %e A221450 Some solutions for n=3 %e A221450 ..0..1..1....0..1..0....1..1..0....1..0..1....1..1..0....0..1..0....1..1..1 %e A221450 ..1..1..0....0..0..0....0..1..0....0..1..0....1..1..0....0..1..1....1..0..0 %e A221450 ..1..1..0....1..1..1....0..1..0....0..0..1....1..1..1....0..0..0....1..1..1 %e A221450 ..1..1..1....0..1..0....1..1..1....1..1..1....0..0..1....1..1..0....1..1..1 %e A221450 ..1..0..1....0..0..1....1..0..1....0..0..1....1..1..0....1..0..1....1..1..1 %K A221450 nonn %O A221450 1,2 %A A221450 _R. H. Hardin_ Jan 17 2013