A203918 Number of (n+2)X5 0..1 arrays with every 3X3 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..1 introduced in row major order

1400, 6050, 21470, 75272, 267066, 949442, 3376768, 12014802, 42694542, 151658528, 538889650, 1914938498, 6805082304, 24183722738, 85939263318, 305389881288, 1085227801658, 3856447692050, 13704254006336, 48699429237698

Offset

1,1

Comments

Column 3 of A203923

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +7*a(n-3) -11*a(n-4) +34*a(n-5) +46*a(n-6) -74*a(n-7) -78*a(n-8) -92*a(n-9) +92*a(n-10) +92*a(n-11) -44*a(n-12) +40*a(n-13) +32*a(n-15) -16*a(n-16) for n>17

Example

Some solutions for n=3
..0..0..1..1..0....0..0..1..0..0....0..1..0..1..1....0..0..1..0..0
..0..1..0..0..0....0..1..0..1..1....1..0..1..1..1....0..1..0..0..1
..1..0..0..0..0....1..0..1..0..1....0..1..1..1..0....1..0..0..1..0
..1..0..0..0..0....1..1..0..1..0....1..1..1..1..0....0..0..1..0..0
..0..1..0..0..0....0..1..1..0..0....1..0..0..1..1....0..1..1..1..0

Crossrefs

Sequence in context: A065214 A336738 A271549 * A178271 A271579 A271712

Adjacent sequences: A203915 A203916 A203917 * A203919 A203920 A203921

Keyword

nonn

Author

R. H. Hardin Jan 07 2012

Status

approved