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 A184122 #8 Jul 22 2025 09:26:54 %S A184122 10,86,561,2861,12068,43947,142376,419213,1139569,2894178,6931366, %T A184122 15770131,34291532,71619470,144269412,281284873,532422712,980922994, %U A184122 1763049635,3097467201,5328692624,8990408705,14896447100,24269860485 %N A184122 Number of nX2 0..3 arrays with rows and columns in nondecreasing order. %C A184122 Column 2 of A184129 %H A184122 R. H. Hardin, <a href="/A184122/b184122.txt">Table of n, a(n) for n = 1..200</a> %F A184122 Empirical: a(n)=16*a(n-1)-120*a(n-2)+560*a(n-3)-1820*a(n-4)+4368*a(n-5)-8008*a(n-6)+11440*a(n-7)-12870*a(n-8)+11440*a(n-9)-8008*a(n-10)+4368*a(n-11)-1820*a(n-12)+560*a(n-13)-120*a(n-14)+16*a(n-15)-a(n-16) (=polynomial of degree 15) %e A184122 Some solutions for 3X2 %e A184122 ..0..1....2..2....0..1....0..2....0..1....2..3....0..3....0..2....1..2....1..2 %e A184122 ..0..1....2..2....2..0....1..3....3..0....2..3....2..3....1..2....2..0....1..2 %e A184122 ..3..3....2..3....2..2....2..2....3..1....3..1....2..3....2..1....2..3....3..0 %K A184122 nonn %O A184122 1,1 %A A184122 _R. H. Hardin_ Jan 09 2011