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A183657
Number of (n+1) X 5 0..5 arrays with every 2 X 2 subblock summing to 10.
1
16626, 43986, 135966, 469146, 1755246, 6990906, 29275086, 127755066, 577190766, 2686295226, 12829230606, 62680963386, 312535936686, 1587207989946, 8196463880526, 42981002402106, 228591556161006, 1231705534203066
OFFSET
1,1
COMMENTS
Column 4 of A183662.
LINKS
FORMULA
Empirical: a(n) = 21*a(n-1) - 175*a(n-2) + 735*a(n-3) - 1624*a(n-4) + 1764*a(n-5) - 720*a(n-6).
Empirical g.f.: 6*x*(2771 - 50860*x + 353635*x^2 - 1151450*x^3 + 1728024*x^4 - 933120*x^5) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 4*x)*(1 - 5*x)*(1 - 6*x)). - Colin Barker, Apr 02 2018
EXAMPLE
Some solutions for 3 X 5:
..4..2..5..2..2....5..2..4..0..3....3..3..1..3..4....4..0..5..1..4
..1..3..0..3..3....1..2..2..4..3....2..2..4..2..1....4..2..3..1..4
..4..2..5..2..2....5..2..4..0..3....4..2..2..2..5....2..2..3..3..2
CROSSREFS
Cf. A183662.
Sequence in context: A236638 A250930 A210272 * A247693 A170788 A057329
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 06 2011
STATUS
approved