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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 1
225704, 1008200, 3376768, 11309768, 38569884, 132454088, 457030140, 1565984648, 5374946016, 18438912648, 63255158600, 216863808200, 742452142224, 2541971328800, 8704656142336, 29820541899848, 102157313490680 (list; graph; refs; listen; history; text; internal format)
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

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Last modified October 24 13:06 EDT 2021. Contains 348231 sequences. (Running on oeis4.)