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A224564 Number of (n+3) X 7 0..1 matrices with each 4 X 4 subblock idempotent. 1
739, 517, 629, 752, 861, 1091, 1433, 1871, 2390, 3108, 4136, 5571, 7493, 10098, 13695, 18692, 25575, 35024, 48030, 65994, 90801, 125014, 172189, 237285, 327144, 451169, 622321, 858522, 1184534, 1634520, 2255606, 3112842, 4296038, 5929165, 8183322 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A224568.

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) - 7*a(n-2) + 8*a(n-3) - 6*a(n-4) + a(n-5) + 3*a(n-6) - 4*a(n-7) + 3*a(n-8) - a(n-9) for n>11.

Empirical g.f.: x*(739 - 2439*x + 3734*x^2 - 4057*x^3 + 2554*x^4 + 242*x^5 - 1880*x^6 + 2176*x^7 - 1413*x^8 + 314*x^9 + 28*x^10) / ((1 - x)^3*(1 + x^2)*(1 - x - x^4)). - Colin Barker, Sep 01 2018

EXAMPLE

Some solutions for n=3:

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

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

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

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

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

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

CROSSREFS

Cf. A224568.

Sequence in context: A337738 A204289 A204285 * A077723 A235466 A202417

Adjacent sequences:  A224561 A224562 A224563 * A224565 A224566 A224567

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 10 2013

STATUS

approved

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Last modified March 4 02:14 EST 2021. Contains 341773 sequences. (Running on oeis4.)