A207121 Number of nX6 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically

21, 441, 2499, 14161, 49861, 175561, 475984, 1290496, 2958144, 6780816, 13816824, 28153636, 52561236, 98128836, 171205398, 298702089, 493723461, 816073489, 1290571359, 2040961329, 3110933397, 4741837321, 7005780418, 10350620644

Offset

1,1

Comments

Column 6 of A207123

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +10*a(n-2) -22*a(n-3) -44*a(n-4) +110*a(n-5) +110*a(n-6) -330*a(n-7) -165*a(n-8) +660*a(n-9) +132*a(n-10) -924*a(n-11) +924*a(n-13) -132*a(n-14) -660*a(n-15) +165*a(n-16) +330*a(n-17) -110*a(n-18) -110*a(n-19) +44*a(n-20) +22*a(n-21) -10*a(n-22) -2*a(n-23) +a(n-24)

Example

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

Crossrefs

Sequence in context: A207246 A208167 A207066 * A207440 A188691 A207430

Adjacent sequences: A207118 A207119 A207120 * A207122 A207123 A207124

Keyword

nonn

Author

R. H. Hardin Feb 15 2012

Status

approved