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A224567
Number of (n+3) X 10 0..1 matrices with each 4 X 4 subblock idempotent.
1
1852, 1044, 1232, 1433, 1614, 1997, 2526, 3175, 3917, 4951, 6416, 8429, 11076, 14646, 19563, 26372, 35700, 48467, 66013, 90227, 123621, 169631, 233029, 320480, 441157, 607673, 837409, 1154415, 1591910, 2195730, 3029088, 4179251, 5766701, 7957760
OFFSET
1,1
COMMENTS
Column 7 of A224568.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) - 2*a(n-2) - 2*a(n-3) + 4*a(n-4) - 3*a(n-5) + 2*a(n-7) -a(n-8) for n>10.
Empirical g.f.: x*(1852 - 4512*x + 1804*x^2 + 3529*x^3 - 5541*x^4 + 3865*x^5 + 833*x^6 - 2921*x^7 + 1045*x^8 + 36*x^9) / ((1 - x)^3*(1 + x)*(1 - x - x^4)). Colin Barker, Sep 01 2018
EXAMPLE
Some solutions for n=3:
..1..1..1..1..1..1..1..0..0..0....1..0..0..0..1..0..0..0..0..0
..0..0..0..0..0..0..0..0..0..0....1..0..0..0..1..0..0..0..0..0
..0..0..0..0..0..0..0..0..0..0....0..0..0..0..1..0..0..0..0..0
..0..0..0..0..0..0..0..0..0..0....0..0..0..0..1..0..0..0..0..0
..0..0..0..0..0..0..0..0..0..0....0..0..0..0..1..0..0..0..0..0
..0..1..0..1..1..1..1..1..1..1....0..0..0..0..1..0..0..0..0..1
CROSSREFS
Cf. A224568.
Sequence in context: A031674 A031541 A031721 * A303272 A128289 A023044
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 10 2013
STATUS
approved