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 A234975 Number of (n+1) X (1+1) 0..4 arrays with every 2 X 2 subblock having the sum of the absolute values of the edge differences equal to 8. 1

%I #11 Oct 16 2018 11:25:13

%S 182,1664,14420,127982,1127550,9962574,87941706,776556490,6856434758,

%T 60540092874,534541037814,4719777004110,41673602284166,

%U 367960260263026,3248932448319154,28686692988827766,253291301375224138

%N Number of (n+1) X (1+1) 0..4 arrays with every 2 X 2 subblock having the sum of the absolute values of the edge differences equal to 8.

%H R. H. Hardin, <a href="/A234975/b234975.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 9*a(n-1) + 13*a(n-2) - 134*a(n-3) + a(n-4) + 480*a(n-5) - 224*a(n-6) - 96*a(n-7).

%F Empirical g.f.: 2*x*(91 + 13*x - 1461*x^2 + 479*x^3 + 5523*x^4 - 2943*x^5 - 1197*x^6) / (1 - 9*x - 13*x^2 + 134*x^3 - x^4 - 480*x^5 + 224*x^6 + 96*x^7). - _Colin Barker_, Oct 16 2018

%e Some solutions for n=4:

%e ..4..1....4..3....0..4....4..1....4..1....0..1....4..0....1..3....2..0....3..0

%e ..4..0....1..4....0..4....2..3....0..0....1..4....0..0....2..0....2..4....4..0

%e ..4..0....0..1....1..3....0..4....2..4....0..3....4..3....3..4....0..1....4..1

%e ..3..0....1..4....3..1....1..3....0..4....4..4....2..0....3..0....4..1....4..0

%e ..2..3....0..3....1..3....4..2....1..1....2..0....4..1....4..0....3..0....3..1

%Y Column 1 of A234982.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 02 2014

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Last modified December 4 07:54 EST 2023. Contains 367557 sequences. (Running on oeis4.)