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A253835 Number of (n+2)X(2+2) 0..1 arrays with every 3X3 subblock diagonal sum plus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally 1

%I #4 Jan 16 2015 13:06:49

%S 2440,6339,19970,60741,129378,265117,517697,920743,1570681,2618604,

%T 4231022,6636278,10253068,15585443,23416148,34730393,51160002,

%U 74729961,108671350,156842600,225956004,324026686,464035121,661461991,943337179

%N Number of (n+2)X(2+2) 0..1 arrays with every 3X3 subblock diagonal sum plus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally

%C Column 2 of A253841

%H R. H. Hardin, <a href="/A253835/b253835.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) -a(n-2) +6*a(n-4) -12*a(n-5) +8*a(n-6) -4*a(n-7) -7*a(n-8) +18*a(n-9) -21*a(n-10) +24*a(n-11) -9*a(n-12) -6*a(n-13) +21*a(n-14) -36*a(n-15) +24*a(n-16) -12*a(n-17) -2*a(n-18) +16*a(n-19) -17*a(n-20) +18*a(n-21) -9*a(n-22) +4*a(n-24) -8*a(n-25) +4*a(n-26) for n>30

%e Some solutions for n=4

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 16 2015

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Last modified July 14 02:38 EDT 2024. Contains 374291 sequences. (Running on oeis4.)