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Number of (n+2) X (2+2) 0..1 arrays with every 3 X 3 subblock diagonal maximum plus antidiagonal minimum nondecreasing horizontally and vertically.
1

%I #6 Jun 16 2023 15:37:53

%S 3264,30848,291392,2654464,22951616,196953728,1698464064,14584992256,

%T 125182611904,1074628170624,9217329596480,79050564905728,

%U 678127033451712,5816974582413440,49896386833688384,428003374084414464

%N Number of (n+2) X (2+2) 0..1 arrays with every 3 X 3 subblock diagonal maximum plus antidiagonal minimum nondecreasing horizontally and vertically.

%C Column 2 of A253863.

%H R. H. Hardin, <a href="/A253857/b253857.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 14*a(n-1) -46*a(n-2) -42*a(n-3) +624*a(n-4) -4070*a(n-5) +23726*a(n-6) -143310*a(n-7) +364913*a(n-8) +1129936*a(n-9) -6925152*a(n-10) +15765760*a(n-11) -48494080*a(n-12) +157092864*a(n-13) -333556224*a(n-14) +23502848*a(n-15) +1872896000*a(n-16) -4361814016*a(n-17) +12360941568*a(n-18) -45439909888*a(n-19) +98790080512*a(n-20) -104990769152*a(n-21) -49694113792*a(n-22) +350694146048*a(n-23) -1042871746560*a(n-24) +3605625044992*a(n-25) -7769595838464*a(n-26) +8796093022208*a(n-27) -4947802324992*a(n-28) +1099511627776*a(n-29).

%e Some solutions for n=2

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

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

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

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

%Y Cf. A253863.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 17 2015