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 A219689 #6 Jul 23 2025 00:36:44 %S A219689 15,35,269,1688,8964,44736,219216,1062133,5046678,23361295,105246826, %T A219689 462379361,1984693730,8329188237,34174571720,137072090506, %U A219689 537533392034,2061741321158,7738348853856,28437341923159,102381325106959 %N A219689 Number of 5Xn arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 5Xn array. %C A219689 Row 5 of A219686 %H A219689 R. H. Hardin, <a href="/A219689/b219689.txt">Table of n, a(n) for n = 1..100</a> %e A219689 Some solutions for n=3 %e A219689 ..1..1..1....0..0..0....1..0..0....1..0..0....0..0..0....1..0..0....0..0..0 %e A219689 ..1..1..1....0..0..0....1..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A219689 ..1..1..1....0..0..0....1..0..0....0..0..0....2..0..0....0..0..0....1..1..1 %e A219689 ..2..1..1....0..0..0....1..1..1....0..0..0....2..2..2....0..0..0....1..1..0 %e A219689 ..2..2..2....0..0..2....1..1..1....1..0..0....2..2..2....0..0..0....1..0..0 %K A219689 nonn %O A219689 1,1 %A A219689 _R. H. Hardin_ Nov 25 2012