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 A221433 #9 Jul 23 2025 01:55:24 %S A221433 6,12,12,576,66240,15321600,5411750400,2834466324480,2102110586634240, %T A221433 2130686007341875200,2866934087721639936000,4998512704699099643904000, %U A221433 11064050379110706817558118400,30552674703715743883429360435200 %N A221433 Number of nX3 1..(max n,3) arrays with each row and column having unrepeated values. %C A221433 Column 3 of A221438. %D A221433 RJ Stones, S Lin, X Liu, G Wang, On Computing the Number of Latin Rectangles, Graphs and Combinatorics, Graphs and Combinatorics (2016) 32:1187-1202; DOI 10.1007/s00373-015-1643-1 %H A221433 R. H. Hardin, <a href="/A221433/b221433.txt">Table of n, a(n) for n = 1..58</a> %e A221433 Some solutions for n=3 %e A221433 ..3..2..1....1..2..3....1..2..3....3..1..2....1..3..2....2..1..3....2..3..1 %e A221433 ..2..1..3....2..3..1....3..1..2....2..3..1....3..2..1....3..2..1....1..2..3 %e A221433 ..1..3..2....3..1..2....2..3..1....1..2..3....2..1..3....1..3..2....3..1..2 %Y A221433 Cf. A221438. %K A221433 nonn %O A221433 1,1 %A A221433 _R. H. Hardin_ Jan 16 2013