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A286209 Number of nX1 0..1 arrays with the number of 1s king-move adjacent to some 0 two less than the number of 0s adjacent to some 1. 6

%I

%S 0,0,0,0,0,0,1,3,10,24,60,134,304,656,1420,2996,6312,13112,27167,

%T 55825,114412,233282,474563,962159,1947098,3931288,7925708,15952866,

%U 32072580,64404708,129213082,259009006,518818124,1038549912,2077775396,4154785904,8304424080

%N Number of nX1 0..1 arrays with the number of 1s king-move adjacent to some 0 two less than the number of 0s adjacent to some 1.

%H Alois P. Heinz, <a href="/A286209/b286209.txt">Table of n, a(n) for n = 0..3327</a> (terms n = 1..210 from R. H. Hardin)

%e All solutions for n=7

%e ..0. .0. .0

%e ..1. .0. .1

%e ..0. .1. .0

%e ..0. .0. .0

%e ..0. .0. .1

%e ..1. .1. .0

%e ..0. .0. .0

%p b:= proc(n, t, h, c) option remember; `if`(abs(c-2)>n, 0, `if`(n=0, 1,

%p b(n-1, [1, 3, 1][t], 2, c-`if`(h=3, 1, 0))+

%p b(n-1, 2, [1, 3, 1][h], c+`if`(t=3, 1, 0))))

%p end:

%p a:= n-> b(n, 1$2, 0):

%p seq(a(n), n=0..40); # _Alois P. Heinz_, Apr 29 2019

%Y Column k=1 of A286216.

%Y Column k=2 of A307796.

%K nonn

%O 0,8

%A _R. H. Hardin_, May 04 2017

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Last modified May 25 03:50 EDT 2019. Contains 323539 sequences. (Running on oeis4.)