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%I #4 Mar 25 2018 11:35:42
%S 2,23,118,564,2793,14394,71564,359659,1808256,9076074,45607585,
%T 229124216,1151098126,5783024867,29053401570,145961054556,
%U 733293062029,3683989357618,18507978344520,92982190589347,467132961135876
%N Number of nX4 0..1 arrays with every element equal to 1, 2 or 4 horizontally or vertically adjacent elements, with upper left element zero.
%C Column 4 of A301669.
%H R. H. Hardin, <a href="/A301665/b301665.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) +15*a(n-2) -6*a(n-3) -91*a(n-4) -75*a(n-5) +327*a(n-6) +398*a(n-7) -880*a(n-8) -1862*a(n-9) -823*a(n-10) +79*a(n-11) +5465*a(n-12) +26064*a(n-13) +45144*a(n-14) -31786*a(n-15) -99377*a(n-16) -89293*a(n-17) +55985*a(n-18) -111034*a(n-19) -138395*a(n-20) +141455*a(n-21) +486139*a(n-22) +96486*a(n-23) -536176*a(n-24) +16636*a(n-25) +98232*a(n-26) +573306*a(n-27) -822404*a(n-28) +47656*a(n-29) +698032*a(n-30) +48550*a(n-31) -264890*a(n-32) -1009366*a(n-33) +282680*a(n-34) +950924*a(n-35) -62788*a(n-36) -370362*a(n-37) +6650*a(n-38) -1020118*a(n-39) +1292800*a(n-40) -896852*a(n-41) +1410204*a(n-42) -572266*a(n-43) -344184*a(n-44) -135916*a(n-45) -198212*a(n-46) +723258*a(n-47) -188503*a(n-48) -34287*a(n-49) -130327*a(n-50) +23396*a(n-51) +62935*a(n-52) -53445*a(n-53) +2017*a(n-54) +6884*a(n-55) +16010*a(n-56) +6076*a(n-57) -4473*a(n-58) -7867*a(n-59) -461*a(n-60) +2650*a(n-61) +830*a(n-62) -536*a(n-63) -391*a(n-64) +73*a(n-65) +91*a(n-66) +12*a(n-67) -13*a(n-68) -3*a(n-69) +a(n-70)
%e Some solutions for n=5
%e ..0..1..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..0. .0..0..0..1
%e ..0..1..0..1. .0..1..1..1. .1..1..1..0. .0..1..1..0. .1..1..0..1
%e ..0..0..1..1. .1..1..0..1. .0..0..0..1. .1..1..0..1. .0..1..1..1
%e ..1..0..0..0. .0..0..0..0. .0..1..1..1. .0..0..0..1. .0..0..0..0
%e ..1..1..1..1. .1..1..0..0. .0..1..0..0. .0..1..1..1. .1..1..1..0
%Y Cf. A301669.
%K nonn
%O 1,1
%A _R. H. Hardin_, Mar 25 2018
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