A206885 Number of nX4 0..1 arrays avoiding 0 1 0 horizontally and 1 0 0 vertically

12, 144, 1103, 7878, 51800, 330951, 2070564, 12830802, 79045687, 485544940, 2977554668, 18243896709, 111730524932, 684100356564, 4188038973519, 25637266851722, 156933921465968, 960624347689059, 5880116589637756

Offset

1,1

Comments

Column 4 of A206889

Links

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

Formula

Empirical: a(n) = 11*a(n-1) -14*a(n-2) -193*a(n-3) +496*a(n-4) +1310*a(n-5) -4382*a(n-6) -4486*a(n-7) +18762*a(n-8) +8132*a(n-9) -44696*a(n-10) -6382*a(n-11) +61529*a(n-12) -2253*a(n-13) -48436*a(n-14) +8149*a(n-15) +20392*a(n-16) -5560*a(n-17) -3842*a(n-18) +1352*a(n-19) +192*a(n-20) -80*a(n-21)

Example

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

Crossrefs

Sequence in context: A207001 A206781 A188769 * A206890 A188758 A207090

Adjacent sequences: A206882 A206883 A206884 * A206886 A206887 A206888

Keyword

nonn

Author

R. H. Hardin Feb 13 2012

Status

approved