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A224557 Number of (n+2) X 8 0..1 matrices with each 3 X 3 subblock idempotent. 1
418, 351, 451, 551, 740, 992, 1298, 1742, 2382, 3267, 4530, 6362, 9003, 12826, 18395, 26514, 38360, 55674, 81001, 118063, 172323, 251789, 368191, 538722, 788583, 1154705, 1691212, 2477429, 3629612, 5318141, 7792721, 11419313, 16734258 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 6 of A224559.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 5*a(n-3) - 4*a(n-4) + 3*a(n-5) - a(n-6) for n>8.

Empirical g.f.: x*(418 - 1321*x + 1555*x^2 - 1237*x^3 + 1159*x^4 - 767*x^5 + 184*x^6 + 4*x^7) / ((1 - x)^3*(1 - x - x^3)). - Colin Barker, Aug 31 2018

EXAMPLE

Some solutions for n=3:

..0..0..0..0..0..0..0..0....1..1..0..0..0..0..0..0....1..0..0..1..0..0..0..0

..1..1..1..1..1..1..1..1....0..0..0..0..0..0..0..0....1..0..0..1..0..0..1..0

..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0....0..0..0..1..0..0..1..0

..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0....0..0..0..1..0..0..1..0

..0..0..0..0..1..1..1..1....1..0..1..1..1..1..1..1....0..0..0..1..0..0..1..0

CROSSREFS

Cf. A224559.

Sequence in context: A239191 A324613 A202527 * A292422 A328497 A138062

Adjacent sequences:  A224554 A224555 A224556 * A224558 A224559 A224560

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 10 2013

STATUS

approved

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Last modified October 21 22:16 EDT 2021. Contains 348155 sequences. (Running on oeis4.)