A253697 Number of (n+1)X(7+1) 0..1 arrays with every 2X2 subblock ne-sw antidiagonal difference unequal to its neighbors horizontally and nw+se diagonal sum unequal to its neighbors vertically

4456, 1984, 1608, 1790, 2626, 4010, 6558, 10428, 16796, 26124, 42686, 69008, 112928, 182646, 298374, 486940, 796612, 1296330, 2121532, 3469558, 5681088, 9275818, 15194178, 24867946, 40742556, 66629916, 109153524, 178773544, 292896144

Offset

1,1

Comments

Column 7 of A253698

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-2) +2*a(n-3) +4*a(n-4) +2*a(n-5) -7*a(n-6) -17*a(n-7) -7*a(n-8) -8*a(n-9) -11*a(n-10) +36*a(n-11) +42*a(n-12) -a(n-13) +28*a(n-14) +17*a(n-15) -53*a(n-16) +5*a(n-17) +12*a(n-18) -72*a(n-19) -20*a(n-20) -2*a(n-21) -54*a(n-22) +10*a(n-23) +32*a(n-24) -12*a(n-25) +22*a(n-26) +24*a(n-27) -a(n-28) +16*a(n-29) +8*a(n-30) +4*a(n-32) for n>38

Example

Some solutions for n=4
..0..1..1..0..0..1..1..0....0..0..1..0..0..1..1..0....1..1..0..1..1..0..0..1
..1..0..0..1..0..1..1..0....1..0..0..1..1..0..1..0....0..1..1..0..0..1..0..1
..0..1..0..1..1..0..0..1....0..1..1..0..1..0..0..1....1..0..0..1..0..1..0..0
..0..1..1..0..0..1..0..1....0..1..1..0..0..1..1..1....0..1..0..1..0..0..1..1
..1..0..0..1..0..1..0..0....1..0..0..1..1..0..1..1....0..1..0..0..1..1..0..1

Crossrefs

Sequence in context: A236906 A184611 A279042 * A253704 A235015 A185767

Adjacent sequences: A253694 A253695 A253696 * A253698 A253699 A253700

Keyword

nonn

Author

R. H. Hardin, Jan 09 2015

Status

approved