A203922 Number of (n+2)X9 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

225704, 1008200, 3376768, 11309768, 38569884, 132454088, 457030140, 1565984648, 5374946016, 18438912648, 63255158600, 216863808200, 742452142224, 2541971328800, 8704656142336, 29820541899848, 102157313490680

Offset

1,1

Comments

Column 7 of A203923

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +2*a(n-3) +4*a(n-4) +24*a(n-5) -104*a(n-6) +301*a(n-7) -972*a(n-8) +2951*a(n-9) +4454*a(n-10) -8159*a(n-11) +3837*a(n-12) +13919*a(n-13) -26933*a(n-14) -91244*a(n-15) +142632*a(n-16) -570464*a(n-17) -98729*a(n-18) +603130*a(n-19) -1303688*a(n-20) +752149*a(n-21) +3907255*a(n-22) -1500486*a(n-23) -2419833*a(n-24) +46150970*a(n-25) -18016427*a(n-26) -44844189*a(n-27) +17393987*a(n-28) -13261937*a(n-29) +5424393*a(n-30) +454779*a(n-31) -971074*a(n-32) +371293*a(n-33) -12623962*a(n-35) +4826809*a(n-36) for n>41

Example

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

Crossrefs

Sequence in context: A215402 A204743 A048427 * A237032 A067141 A234775

Adjacent sequences: A203919 A203920 A203921 * A203923 A203924 A203925

Keyword

nonn

Author

R. H. Hardin Jan 07 2012

Status

approved