cp's OEIS Frontend

A207920 Number of 5Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 0 and 1 0 1 vertically.

%I A207920 #7 Jul 22 2025 21:00:04
%S A207920 16,256,1152,5371,21145,86255,366330,1520815,6276388,26127518,
%T A207920 108694123,451081599,1873587315,7785944494,32343169917,134348128428,
%U A207920 558128458658,2318624670321,9631925841375,40012938910533,166222764096548
%N A207920 Number of 5Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 0 and 1 0 1 vertically.
%C A207920 Row 5 of A207918
%H A207920 R. H. Hardin, <a href="/A207920/b207920.txt">Table of n, a(n) for n = 1..210</a>
%F A207920 Empirical: a(n) = a(n-1) +2*a(n-2) +37*a(n-3) +59*a(n-4) +24*a(n-5) -269*a(n-6) -770*a(n-7) -667*a(n-8) +1180*a(n-9) +3322*a(n-10) +2975*a(n-11) -1689*a(n-12) -6648*a(n-13) -6577*a(n-14) -387*a(n-15) +5843*a(n-16) +7354*a(n-17) +3010*a(n-18) -2018*a(n-19) -3068*a(n-20) -2386*a(n-21) +556*a(n-22) +777*a(n-23) +764*a(n-24) -259*a(n-25) -552*a(n-26) -503*a(n-27) -97*a(n-28) +10*a(n-29) +168*a(n-30) +19*a(n-31) +51*a(n-32) -19*a(n-33) +10*a(n-34) -3*a(n-35) +3*a(n-36) for n>38
%e A207920 Some solutions for n=4
%e A207920 ..0..0..1..1....0..1..1..0....0..0..1..1....1..1..0..0....1..1..0..0
%e A207920 ..1..1..0..0....0..0..1..1....0..1..0..0....1..1..1..1....1..0..0..1
%e A207920 ..1..1..0..0....0..0..1..1....0..1..0..0....0..0..1..1....0..0..1..1
%e A207920 ..1..0..0..1....0..0..1..1....0..1..0..0....0..0..1..0....0..1..1..1
%e A207920 ..0..0..1..1....0..1..0..0....0..1..1..0....1..1..1..0....0..1..0..0
%K A207920 nonn
%O A207920 1,1
%A A207920 _R. H. Hardin_ Feb 21 2012