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A224561 Number of (n+3) X 4 0..1 matrices with each 4 X 4 subblock idempotent. 1
452, 370, 512, 739, 990, 1345, 1852, 2659, 3846, 5589, 8064, 11675, 16954, 24757, 36196, 52963, 77458, 113341, 165916, 243035, 356062, 521713, 764408, 1120079, 1641326, 2405317, 3525004, 5165987, 7570886, 11095421, 16260864, 23831255 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 1 of A224568.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + a(n-4) - 2*a(n-5) + 2*a(n-6) - 2*a(n-7) + a(n-8) for n>10.
Empirical g.f.: x*(452 - 986*x + 758*x^2 - 139*x^3 - 513*x^4 + 614*x^5 - 628*x^6 + 597*x^7 - 168*x^8 - 13*x^9) / ((1 - x)^2*(1 + x)*(1 - x + x^2)*(1 - x - x^3)). - Colin Barker, Sep 01 2018
EXAMPLE
Some solutions for n=3:
..1..0..0..0....1..0..1..0....1..0..0..0....0..0..0..0....1..1..0..1
..0..1..0..1....0..1..1..1....0..0..0..0....0..1..1..1....0..0..0..0
..0..0..0..0....0..0..0..0....0..0..1..1....0..0..0..0....0..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..1..0..1....0..1..1..1....0..0..1..1....0..1..1..1....1..1..1..1
..0..1..0..1....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
CROSSREFS
Cf. A224568.
Sequence in context: A128922 A224560 A224568 * A116308 A183636 A222823
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 10 2013
STATUS
approved

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Last modified July 21 15:14 EDT 2024. Contains 374474 sequences. (Running on oeis4.)