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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.

A204975 Number of nX5 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically, diagonally or antidiagonally, and new values 0..2 introduced in row major order.

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%I A204975 #8 Jul 22 2025 18:29:00
%S A204975 30,5400,226908,11815256,594430765,30057359681,1519010368414,
%T A204975 76757855124562,3878731054806384,196001179244804717,
%U A204975 9904372451888881080,500490203444826245265,25290888836528806246336,1278005232465153039958786
%N A204975 Number of nX5 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically, diagonally or antidiagonally, and new values 0..2 introduced in row major order.
%C A204975 Column 5 of A204978
%H A204975 R. H. Hardin, <a href="/A204975/b204975.txt">Table of n, a(n) for n = 1..210</a>
%e A204975 Some solutions for n=5
%e A204975 ..0..1..2..0..1....0..1..0..2..1....0..0..1..2..0....0..1..2..0..1
%e A204975 ..2..1..2..2..0....2..1..1..2..0....1..1..2..0..2....1..2..1..0..1
%e A204975 ..0..0..1..2..0....1..0..1..0..1....2..0..2..1..0....1..2..0..2..0
%e A204975 ..0..1..0..0..1....1..2..2..0..1....0..1..0..1..0....0..1..1..0..0
%e A204975 ..2..2..1..2..1....2..1..2..2..0....1..0..0..2..2....2..0..2..1..1
%K A204975 nonn
%O A204975 1,1
%A A204975 _R. H. Hardin_ Jan 21 2012

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