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A303620 Number of nX4 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. 1

%I #4 Apr 27 2018 09:52:51

%S 1,20,68,325,1870,10741,62207,363485,2135551,12586013,74323727,

%T 439462339,2600501501,15395919313,91177465195,540072985865,

%U 3199404347759,18954749501705,112301887289875,665378205627245,3942374534440139

%N Number of nX4 0..1 arrays with every element equal to 0, 2, 3, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

%C Column 4 of A303624.

%H R. H. Hardin, <a href="/A303620/b303620.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 9*a(n-1) -19*a(n-2) +19*a(n-3) -91*a(n-4) +33*a(n-5) -46*a(n-6) +295*a(n-7) +125*a(n-8) +527*a(n-9) -181*a(n-10) -44*a(n-11) -219*a(n-12) -360*a(n-13) +52*a(n-14) -131*a(n-15) -93*a(n-16) +23*a(n-17) +10*a(n-18) +70*a(n-19) +14*a(n-20) -16*a(n-21) +24*a(n-22) for n>24

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A303624.

%K nonn

%O 1,2

%A _R. H. Hardin_, Apr 27 2018

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Last modified April 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)