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A230659 Number of n X 5 0..2 black square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value 2-x(i,j). 1
0, 15, 135, 531, 8613, 28161, 477279, 1539207, 26178201, 84335553, 1434726783, 4621740687, 78627215025, 253283346081, 4308981442911, 13880597644287, 236143613924865, 760693546670625, 12941296146524511, 41688023124390687 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
Empirical: a(n) = 59*a(n-2) - 230*a(n-4) - 2*a(n-6) + 32*a(n-8) for n>10.
Empirical g.f.: 3*x^2*(5 + 45*x - 118*x^2 + 216*x^3 + 94*x^4 + 54*x^5 - 44*x^6 - 16*x^8) / (1 - 59*x^2 + 230*x^4 + 2*x^6 - 32*x^8). - Colin Barker, Sep 22 2018
EXAMPLE
Some solutions for n=5:
..x..0..x..0..x....x..0..x..1..x....x..2..x..0..x....x..0..x..2..x
..2..x..0..x..2....2..x..2..x..1....0..x..0..x..2....2..x..2..x..0
..x..2..x..2..x....x..2..x..1..x....x..2..x..0..x....x..2..x..2..x
..0..x..2..x..1....0..x..1..x..0....2..x..0..x..1....0..x..0..x..1
..x..0..x..1..x....x..1..x..2..x....x..0..x..1..x....x..2..x..1..x
CROSSREFS
Column 5 of A230661.
Sequence in context: A348212 A289421 A201138 * A228583 A027630 A027629
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 27 2013
STATUS
approved

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Last modified May 26 01:16 EDT 2024. Contains 372807 sequences. (Running on oeis4.)