A260469 Number of (n+2)X(2+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000000 00000001 or 00010101

49, 92, 213, 471, 1085, 2562, 5891, 13530, 31372, 72451, 166919, 385563, 890572, 2054927, 4743628, 10953016, 25283529, 58363941, 134740753, 311052242, 718052661, 1657646568, 3826724610, 8834001277, 20393409965, 47078589297

Offset

1,1

Comments

Column 2 of A260475

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) +a(n-4) -3*a(n-5) -3*a(n-6) +a(n-7) +2*a(n-8) -a(n-9) -5*a(n-10) -5*a(n-11) -2*a(n-15) -2*a(n-16) for n>17

Example

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

Crossrefs

Cf. A260475

Sequence in context: A146064 A224905 A224846 * A275419 A031180 A039427

Adjacent sequences: A260466 A260467 A260468 * A260470 A260471 A260472

Keyword

nonn

Author

R. H. Hardin, Jul 26 2015

Status

approved