A224564 Number of (n+3) X 7 0..1 matrices with each 4 X 4 subblock idempotent.

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

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