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A251890 Number of (n+2) X (4+2) 0..3 arrays with every 3 X 3 subblock row and column sum not 2 3 6 or 7 and every diagonal and antidiagonal sum 2 3 6 or 7. 2
1280, 530, 778, 1316, 1958, 2660, 4490, 7250, 10634, 17954, 28994, 42530, 71810, 115970, 170114, 287234, 463874, 680450, 1148930, 1855490, 2721794, 4595714, 7421954, 10887170, 18382850, 29687810, 43548674, 73531394, 118751234 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 4 of A251894.
LINKS
FORMULA
Empirical: a(n) = a(n-1) + 4*a(n-3) - 4*a(n-4) for n>9.
Empirical g.f.: 2*x*(640 - 375*x + 124*x^2 - 2291*x^3 + 1821*x^4 - 145*x^5 - 161*x^6 + 96*x^7 + 288*x^8) / ((1 - x)*(1 - 4*x^3)). - Colin Barker, Mar 20 2018
EXAMPLE
Some solutions for n=4:
..1..1..2..1..1..2....2..3..3..2..0..3....0..1..0..0..1..3....0..0..1..0..0..1
..3..0..1..0..0..1....0..2..2..0..2..2....1..3..1..1..3..1....1..1..3..1..1..2
..0..0..1..0..0..1....2..3..3..2..3..3....0..1..0..0..1..0....0..0..1..0..0..1
..1..1..3..1..1..2....2..3..3..2..3..3....0..1..0..0..1..0....0..0..1..0..0..1
..0..0..1..0..0..1....0..2..2..0..2..2....1..3..1..1..3..1....1..1..2..1..1..2
..3..0..1..0..0..1....2..3..3..2..0..3....3..1..0..0..1..0....0..0..1..0..0..1
CROSSREFS
Cf. A251894.
Sequence in context: A251097 A031798 A293923 * A251889 A251886 A234137
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 10 2014
STATUS
approved

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Last modified April 18 22:18 EDT 2024. Contains 371782 sequences. (Running on oeis4.)