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Number of (n+2) X 4 0..1 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..1 introduced in row major order.
1

%I #7 Nov 17 2022 18:15:05

%S 1606,21537,288483,3849194,51416847,686818023,9173723833,122534242638,

%T 1636701798670,21861555803429,292006616968228,3900356724250647,

%U 52097388691830853,695869150316313516,9294782075856717489

%N Number of (n+2) X 4 0..1 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..1 introduced in row major order.

%C Column 2 of A205273.

%H R. H. Hardin, <a href="/A205267/b205267.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 10*a(n-1) +29*a(n-2) +224*a(n-3) -115*a(n-4) -313*a(n-5) -4867*a(n-6) -687*a(n-7) +4061*a(n-8) +32593*a(n-9) +11681*a(n-10) -96770*a(n-11) -145988*a(n-12) +162008*a(n-13) +921965*a(n-14) +730858*a(n-15) -2124198*a(n-16) -4434047*a(n-17) +323452*a(n-18) +8244675*a(n-19) +7785366*a(n-20) -4131170*a(n-21) -15532147*a(n-22) -9306916*a(n-23) +8514045*a(n-24) +16456145*a(n-25) +8373294*a(n-26) -4797322*a(n-27) -9882396*a(n-28) -5985701*a(n-29) -1246612*a(n-30) +1250396*a(n-31) +2285451*a(n-32) +1994143*a(n-33) +762736*a(n-34) -168574*a(n-35) -227331*a(n-36) -116303*a(n-37) -82075*a(n-38) -33501*a(n-39) -8586*a(n-40) -742*a(n-41) -2354*a(n-42) -192*a(n-43) +256*a(n-44).

%e Some solutions for n=3

%e ..0..1..1..0....0..0..1..1....0..0..1..1....0..0..0..1....0..1..0..0

%e ..0..0..1..1....1..1..0..0....0..0..1..0....1..0..1..0....0..1..1..1

%e ..0..0..1..0....1..1..1..0....1..0..0..0....1..0..1..1....0..0..0..0

%e ..0..0..1..0....0..1..1..1....1..0..1..1....0..0..1..0....1..0..1..0

%e ..1..1..0..0....1..1..0..1....0..0..0..0....1..0..1..1....0..1..0..1

%Y Cf. A205273.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 24 2012