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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A206986 Number of nX7 0..1 arrays avoiding the patterns 0 1 0 or 1 0 1 in any row, column, diagonal or antidiagonal.

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%I A206986 #7 Jul 22 2025 19:53:35
%S A206986 42,1764,2754,18528,106110,539576,2926752,16410772,88554260,477698908,
%T A206986 2619259634,14280032054,77486975514,422191223508,2301460838104,
%U A206986 12521989484576,68163339893844,371278088395874,2021451066772812
%N A206986 Number of nX7 0..1 arrays avoiding the patterns 0 1 0 or 1 0 1 in any row, column, diagonal or antidiagonal.
%C A206986 Column 7 of A206987
%H A206986 R. H. Hardin, <a href="/A206986/b206986.txt">Table of n, a(n) for n = 1..210</a>
%F A206986 Empirical: a(n) = 12*a(n-1) -57*a(n-2) +204*a(n-3) -712*a(n-4) +1629*a(n-5) -2013*a(n-6) -1350*a(n-7) +8857*a(n-8) -2692*a(n-9) +40341*a(n-10) -184639*a(n-11) +267833*a(n-12) -342433*a(n-13) +259406*a(n-14) +82163*a(n-15) +2551670*a(n-16) -1584198*a(n-17) -11211930*a(n-18) +8263359*a(n-19) -650200*a(n-20) +75417795*a(n-21) -127353208*a(n-22) +98617983*a(n-23) -294853523*a(n-24) +293977586*a(n-25) +84609725*a(n-26) -1982930*a(n-27) -37710696*a(n-28) -995272981*a(n-29) +3231800062*a(n-30) -1273045117*a(n-31) -1553881483*a(n-32) -5866183982*a(n-33) +4867153776*a(n-34) +6843320108*a(n-35) -6774230192*a(n-36) -9332999003*a(n-37) +4369010024*a(n-38) +20963390934*a(n-39) +12206097010*a(n-40) -28409016089*a(n-41) -23333909730*a(n-42) +53550932578*a(n-43) +3481744833*a(n-44) -22681916085*a(n-45) -79404231597*a(n-46) +26112200963*a(n-47) +70779977384*a(n-48) -27744834069*a(n-49) -67989382455*a(n-50) +25768829849*a(n-51) +76157982282*a(n-52) +38333688138*a(n-53) -66879893432*a(n-54) -31806232924*a(n-55) +50580641882*a(n-56) -10727919156*a(n-57) +18055489357*a(n-58) -15764909685*a(n-59) +617435579*a(n-60) +857583968*a(n-61) -17821204296*a(n-62) +16562222210*a(n-63) -34783447*a(n-64) -4660345275*a(n-65) +346004180*a(n-66) -2701874206*a(n-67) +3769811175*a(n-68) +185792729*a(n-69) -1834618236*a(n-70) +1190435781*a(n-71) -362298763*a(n-72) -288436772*a(n-73) +286127591*a(n-74) +67688678*a(n-75) -111910582*a(n-76) -1679570*a(n-77) -3663805*a(n-78) +6738647*a(n-79) +7719712*a(n-80) -1187115*a(n-81) +477243*a(n-82) -606196*a(n-83) -270152*a(n-84) +60080*a(n-85) +1536*a(n-86) for n>92
%e A206986 Some solutions for n=4
%e A206986 ..0..1..1..1..1..0..0....0..0..1..1..0..0..1....1..0..0..1..1..1..0
%e A206986 ..1..1..1..1..1..0..0....0..1..1..1..0..0..0....0..0..0..1..1..1..0
%e A206986 ..1..1..1..1..1..0..0....1..1..1..1..0..0..0....0..0..0..1..1..0..0
%e A206986 ..1..1..1..1..1..1..0....1..1..1..0..0..0..1....1..0..0..1..1..0..0
%K A206986 nonn
%O A206986 1,1
%A A206986 _R. H. Hardin_ Feb 14 2012