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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.

A183477 Number of nX3 0..2 arrays with every element equal to either the sum mod 3 of its vertical neighbors or the sum mod 3 of its horizontal neighbors.

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%I A183477 #7 Jul 22 2025 08:59:07
%S A183477 5,39,117,587,2925,12131,58333,270611,1220877,5724163,26403017,
%T A183477 121544939,564597457,2608586447,12062272841,55880316803,258485374601,
%U A183477 1196311279235,5538446306557,25631318490835,118643423750561,549199683026799
%N A183477 Number of nX3 0..2 arrays with every element equal to either the sum mod 3 of its vertical neighbors or the sum mod 3 of its horizontal neighbors.
%C A183477 Column 3 of A183483
%H A183477 R. H. Hardin, <a href="/A183477/b183477.txt">Table of n, a(n) for n = 1..200</a>
%F A183477 Empirical: a(n)=8*a(n-1)-18*a(n-2)+84*a(n-3)-579*a(n-4)+1348*a(n-5)-3464*a(n-6)+18376*a(n-7)-41015*a(n-8)+79527*a(n-9)-334512*a(n-10)+695496*a(n-11)-1111399*a(n-12)+3876831*a(n-13)-7441854*a(n-14)+10184221*a(n-15)-30655065*a(n-16)+54160710*a(n-17)-64701205*a(n-18)+173693460*a(n-19)-281900303*a(n-20)+296755925*a(n-21)-730333225*a(n-22)+1086432175*a(n-23)-1011789825*a(n-24)+2336474256*a(n-25)-3177451713*a(n-26)+2619035208*a(n-27)-5787685442*a(n-28)+7177420278*a(n-29)-5223552815*a(n-30)+11228646436*a(n-31)-12673488056*a(n-32)+8097165320*a(n-33)-17162050486*a(n-34)+17603349821*a(n-35)-9768296437*a(n-36)+20663234591*a(n-37)-19224576837*a(n-38)+9099536459*a(n-39)-19470134294*a(n-40)+16378130019*a(n-41)-6427344807*a(n-42)+14168986173*a(n-43)-10725609446*a(n-44)+3343950376*a(n-45)-7805973809*a(n-46)+5287675974*a(n-47)-1227503579*a(n-48)+3163113462*a(n-49)-1907177092*a(n-50)+293721475*a(n-51)-900778627*a(n-52)+482493019*a(n-53)-34626683*a(n-54)+165703644*a(n-55)-80150140*a(n-56)-3548276*a(n-57)-16126436*a(n-58)+7908948*a(n-59)+2463356*a(n-60)+267632*a(n-61)-411136*a(n-62)-464048*a(n-63)+49264*a(n-64)+9792*a(n-65)+28416*a(n-66)
%e A183477 Some solutions for 4X3
%e A183477 ..1..1..0....1..1..1....0..2..2....1..1..0....1..1..0....2..2..0....1..1..0
%e A183477 ..1..1..0....1..1..0....0..0..0....1..1..0....1..1..0....0..0..0....1..1..0
%e A183477 ..1..1..0....2..2..2....1..0..2....0..0..0....2..2..0....1..0..0....0..0..0
%e A183477 ..1..1..0....2..1..2....1..0..2....0..0..0....2..2..0....1..0..0....2..2..0
%K A183477 nonn
%O A183477 1,1
%A A183477 _R. H. Hardin_ Jan 05 2011