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 A183415 #7 Jul 22 2025 08:56:35 %S A183415 5,34,249,1920,15232,123323,1012996,8413325,70482133,594587235, %T A183415 5044756083,43007895169,368151018388,3162466934006,27248906449457, %U A183415 235414313839524,2038652180610193,17691623325368274,153819626587560407 %N A183415 Number of nX2 0..2 arrays with each sum of a(1..i,1..j) no greater than i*j. %C A183415 Column 2 of A183419 %H A183415 R. H. Hardin, <a href="/A183415/b183415.txt">Table of n, a(n) for n = 1..200</a> %e A183415 Some solutions for 4X2 %e A183415 ..0..0....1..0....1..0....0..0....1..0....0..0....1..0....0..2....0..1....0..0 %e A183415 ..2..2....1..0....0..2....1..2....0..1....0..0....0..2....2..0....0..0....2..2 %e A183415 ..1..0....1..2....0..2....0..1....1..0....0..2....1..2....0..1....2..0....0..1 %e A183415 ..1..0....0..2....2..0....2..2....1..2....2..0....0..2....0..0....0..0....0..1 %K A183415 nonn %O A183415 1,1 %A A183415 _R. H. Hardin_ Jan 04 2011