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 A201831 #7 Jul 22 2025 16:22:02 %S A201831 23,212,1629,11180,71501,434721,2553223,14601638,81799885,450682446, %T A201831 2449953613,13173208338,70201196318,371356326457,1952380236002, %U A201831 10211349328475,53172089972396,275828459680751,1426182115328813 %N A201831 Number of nX3 0..3 arrays with every diagonal, row and column running average nondecreasing rightwards and downwards and diagonally. %C A201831 Column 3 of A201836 %H A201831 R. H. Hardin, <a href="/A201831/b201831.txt">Table of n, a(n) for n = 1..45</a> %e A201831 Some solutions for n=5 %e A201831 ..0..1..1....0..1..1....0..0..1....0..0..1....1..1..1....0..3..3....0..0..2 %e A201831 ..1..1..2....0..1..2....0..0..3....0..1..1....1..1..2....0..3..3....0..3..2 %e A201831 ..1..2..2....1..3..2....2..3..3....0..3..2....1..2..2....3..3..3....2..2..2 %e A201831 ..1..2..2....1..2..2....1..3..3....0..3..3....1..3..3....1..3..3....2..3..3 %e A201831 ..1..2..2....3..3..3....2..3..3....1..3..3....2..2..3....3..3..3....2..3..3 %K A201831 nonn %O A201831 1,1 %A A201831 _R. H. Hardin_ Dec 05 2011