A253692 Number of (n+1)X(2+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

40, 76, 146, 304, 602, 1182, 2416, 4772, 9652, 19152, 38524, 76996, 154072, 308634, 617062, 1236382, 2472602, 4951496, 9907740, 19832536, 39695188, 79445558, 159023072, 318264564, 637042828, 1275004742, 2551980574, 5107782140

Offset

1,1

Comments

Column 2 of A253698

Links

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

Formula

Empirical: a(n) = 4*a(n-2) +2*a(n-3) -2*a(n-4) -a(n-5) -7*a(n-6) -3*a(n-7) +9*a(n-8) +3*a(n-9) +a(n-10) -a(n-11) -6*a(n-12) +4*a(n-14) -a(n-16)

Example

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

Crossrefs

Sequence in context: A260537 A044106 A044487 * A253699 A037975 A317095

Adjacent sequences: A253689 A253690 A253691 * A253693 A253694 A253695

Keyword

nonn

Author

R. H. Hardin, Jan 09 2015

Status

approved