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 A224414 #6 Jul 23 2025 05:10:01 %S A224414 128,2916,16684,52700,129402,284254,590254,1183226,2313915,4440909, %T A224414 8390988,15630228,28711640,51997668,92801492,163153936,282488024, %U A224414 481647192,808773552,1337828696,2180752418,3504587582,5555307682 %N A224414 Number of 7Xn 0..1 arrays with rows unimodal and antidiagonals nondecreasing. %C A224414 Row 7 of A224409 %H A224414 R. H. Hardin, <a href="/A224414/b224414.txt">Table of n, a(n) for n = 1..210</a> %F A224414 Empirical: a(n) = (1/87178291200)*n^14 + (1/958003200)*n^13 + (1/21288960)*n^12 + (23/17418240)*n^11 + (331/12441600)*n^10 + (11671/29030400)*n^9 + (612743/121927680)*n^8 + (25375/497664)*n^7 + (15815113/14515200)*n^6 + (109956869/21772800)*n^5 + (221348047/3421440)*n^4 + (154662289/665280)*n^3 + (81821289727/75675600)*n^2 - (157721/140)*n - 1044 for n>5 %e A224414 Some solutions for n=3 %e A224414 ..0..0..1....1..1..0....0..0..0....0..0..0....0..1..0....1..0..0....0..1..0 %e A224414 ..0..1..1....1..1..0....1..1..0....1..0..0....1..1..0....0..0..0....1..1..0 %e A224414 ..1..1..0....1..0..0....1..0..0....0..0..0....1..0..0....0..0..0....1..0..0 %e A224414 ..1..0..0....0..0..1....0..0..0....1..0..0....0..1..0....1..1..0....0..0..1 %e A224414 ..1..0..0....0..1..0....0..0..0....1..0..0....1..0..0....1..1..0....1..1..0 %e A224414 ..0..0..0....1..0..0....0..0..0....0..0..0....1..0..0....1..0..0....1..1..0 %e A224414 ..0..1..0....0..0..1....0..1..1....0..1..1....0..1..1....0..1..0....1..1..1 %K A224414 nonn %O A224414 1,1 %A A224414 _R. H. Hardin_ Apr 05 2013