A260171 Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000101 or 00010001

74, 167, 419, 1001, 2500, 6344, 15847, 39584, 99741, 250297, 626433, 1572166, 3946872, 9894451, 24814854, 62266809, 156182193, 391707889, 982630798, 2464919670, 6182653471, 15508493498, 38902275855, 97581089767, 244769200723

Offset

1,1

Comments

Column 2 of A260177

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +5*a(n-3) +5*a(n-4) -3*a(n-5) +5*a(n-6) +9*a(n-7) -5*a(n-8) -5*a(n-9) +4*a(n-10) -17*a(n-11) -14*a(n-12) +4*a(n-13) -4*a(n-14) -4*a(n-15) for n>16

Example

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

Crossrefs

Cf. A260177

Sequence in context: A044706 A217991 A105053 * A044406 A044787 A204370

Adjacent sequences: A260168 A260169 A260170 * A260172 A260173 A260174

Keyword

nonn

Author

R. H. Hardin, Jul 17 2015

Status

approved