A253693 Number of (n+1)X(3+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

104, 150, 234, 480, 878, 1472, 2982, 5282, 9880, 18552, 34284, 63796, 119066, 220728, 411972, 765790, 1424918, 2652268, 4936064, 9184756, 17094616, 31807790, 59199066, 110166458, 205014144, 381521314, 710006568, 1321296952, 2458905244

Offset

1,1

Comments

Column 3 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) -6*a(n-6) -12*a(n-7) -6*a(n-8) +2*a(n-9) +5*a(n-10) +11*a(n-11) +5*a(n-12) -5*a(n-13) -a(n-14) -2*a(n-16) +a(n-17) -a(n-19) for n>21

Example

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

Crossrefs

Sequence in context: A054903 A074228 A298505 * A168528 A259767 A234261

Adjacent sequences: A253690 A253691 A253692 * A253694 A253695 A253696

Keyword

nonn

Author

R. H. Hardin, Jan 09 2015

Status

approved