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 A224059 #6 Jul 23 2025 04:58:53 %S A224059 50,984,8854,58814,324702,1557606,6643979,25596389,90177585,293585050, %T A224059 891208427,2542007013,6857916671,17598839738,43168340844,101638636169, %U A224059 230538577645,505352928460,1073534755140,2215475595868,4451276849868 %N A224059 Number of nX3 0..3 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing. %C A224059 Column 3 of A224064 %H A224059 R. H. Hardin, <a href="/A224059/b224059.txt">Table of n, a(n) for n = 1..210</a> %F A224059 Empirical: a(n) = (1/3629463552000)*n^18 + (1/80654745600)*n^17 + (673/1307674368000)*n^16 + (3163/237758976000)*n^15 + (208801/747242496000)*n^14 + (625841/149448499200)*n^13 + (1696897/28740096000)*n^12 + (14064731/28740096000)*n^11 + (339240647/73156608000)*n^10 + (339530671/14631321600)*n^9 + (4767368563/28740096000)*n^8 + (637757023/1026432000)*n^7 + (26329719541/10378368000)*n^6 + (2426824577/339655680)*n^5 + (343572662101/18162144000)*n^4 - (189957341011/9081072000)*n^3 + (1627071089/5834400)*n^2 - (2276993179/3063060)*n + 701 for n>3 %e A224059 Some solutions for n=3 %e A224059 ..3..0..0....0..0..0....0..0..2....2..2..1....1..1..0....1..1..1....2..0..0 %e A224059 ..3..3..1....1..1..0....1..1..2....1..2..3....1..1..1....0..1..3....1..3..2 %e A224059 ..0..3..3....1..2..3....1..1..3....0..2..3....0..1..2....0..1..3....1..1..3 %K A224059 nonn %O A224059 1,1 %A A224059 _R. H. Hardin_ Mar 30 2013