cp's OEIS Frontend

A206937 Number of 4Xn 0..1 arrays avoiding 0 0 0 horizontally and 0 1 1 vertically.

%I A206937 #7 Jul 22 2025 19:49:16
%S A206937 12,144,811,6837,55088,410000,3227589,25102409,193788386,1507133620,
%T A206937 11693492167,90677582325,703826743120,5460755855460,42367807894797,
%U A206937 328752895890725,2550786798536934,19791666524580132,153566455887582047
%N A206937 Number of 4Xn 0..1 arrays avoiding 0 0 0 horizontally and 0 1 1 vertically.
%C A206937 Row 4 of A206936
%H A206937 R. H. Hardin, <a href="/A206937/b206937.txt">Table of n, a(n) for n = 1..210</a>
%F A206937 Empirical: a(n) = -a(n-1) +16*a(n-2) +284*a(n-3) +847*a(n-4) +1819*a(n-5) -6372*a(n-6) -18220*a(n-7) -55347*a(n-8) +68879*a(n-9) +139274*a(n-10) +648892*a(n-11) -473781*a(n-12) -401797*a(n-13) -3963592*a(n-14) +2110836*a(n-15) -80057*a(n-16) +13663197*a(n-17) -5668754*a(n-18) +2666692*a(n-19) -27046299*a(n-20) +8341017*a(n-21) -4950884*a(n-22) +30801116*a(n-23) -6296865*a(n-24) +3755693*a(n-25) -20614026*a(n-26) +2290372*a(n-27) -1349783*a(n-28) +8200897*a(n-29) -284960*a(n-30) +233228*a(n-31) -1895282*a(n-32) -35800*a(n-33) -22846*a(n-34) +234592*a(n-35) +9816*a(n-36) +2512*a(n-37) -12944*a(n-38) -240*a(n-39) -64*a(n-40) +256*a(n-41)
%e A206937 Some solutions for n=4
%e A206937 ..0..1..1..1....1..0..0..1....0..1..0..0....1..0..0..1....1..1..0..1
%e A206937 ..1..0..1..0....0..1..1..1....0..0..1..1....1..1..0..1....1..1..0..1
%e A206937 ..0..0..1..0....1..0..0..1....0..1..0..0....0..0..1..0....0..1..1..0
%e A206937 ..0..0..1..1....0..0..1..1....0..0..1..1....1..1..0..0....0..1..0..0
%K A206937 nonn
%O A206937 1,1
%A A206937 _R. H. Hardin_ Feb 13 2012