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 A223619 #6 Jul 23 2025 04:17:50 %S A223619 29,841,14547,160883,1271969,7795951,39162020,167679972,629671260, %T A223619 2118764468,6495046664,18377663488,48503155274,120433134332, %U A223619 283334050243,635338765283,1364719186775,2820129263963,5627010952649,10875524219289 %N A223619 Number of nX7 0..1 arrays with rows and columns unimodal. %C A223619 Column 7 of A223620 %H A223619 R. H. Hardin, <a href="/A223619/b223619.txt">Table of n, a(n) for n = 1..210</a> %F A223619 Empirical: a(n) = (503/209563200)*n^14 + (6527/155675520)*n^13 + (17/31185)*n^12 + (37901/8553600)*n^11 + (76799/2721600)*n^10 + (46471/362880)*n^9 + (3497567/7620480)*n^8 + (936493/777600)*n^7 + (467419/181440)*n^6 + (320807/77760)*n^5 + (69073271/11975040)*n^4 + (29326111/4989600)*n^3 + (60167903/11642400)*n^2 + (191717/72072)*n + 1 %e A223619 Some solutions for n=4 %e A223619 ..0..0..0..0..0..0..0....0..0..0..0..0..1..1....0..0..0..0..0..0..0 %e A223619 ..0..0..0..1..1..1..0....0..0..1..1..1..1..1....0..0..1..1..1..1..1 %e A223619 ..1..0..0..0..0..0..0....0..1..1..1..1..0..0....1..1..1..1..1..1..1 %e A223619 ..0..1..0..0..0..0..0....0..1..1..1..1..0..0....0..0..1..1..1..1..0 %K A223619 nonn %O A223619 1,1 %A A223619 _R. H. Hardin_ Mar 24 2013