A259995 Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000011 or 00000101

99, 269, 805, 1819, 4383, 12412, 32525, 82616, 222474, 598599, 1577548, 4210492, 11316402, 30215951, 80758149, 216596656, 580222858, 1553421000, 4163544562, 11159591352, 29901049773, 80136519668, 214797758849, 575682349029

Offset

1,1

Comments

Column 2 of A260001

Links

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

Formula

Empirical: a(n) = a(n-1) +2*a(n-2) +10*a(n-3) +5*a(n-4) -19*a(n-5) -33*a(n-6) -45*a(n-7) -a(n-8) +25*a(n-9) +13*a(n-10) +5*a(n-11) +3*a(n-12) +9*a(n-13) +8*a(n-14)

Example

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

Crossrefs

Cf. A260001

Sequence in context: A250734 A260279 A250779 * A125820 A008902 A008882

Adjacent sequences: A259992 A259993 A259994 * A259996 A259997 A259998

Keyword

nonn

Author

R. H. Hardin, Jul 12 2015

Status

approved