A224604 Number of (n+2) X 8 0..2 matrices with each 3 X 3 subblock idempotent.

1045, 894, 1086, 1247, 1609, 2092, 2656, 3497, 4731, 6434, 8878, 12451, 17617, 25112, 36060, 52049, 75403, 109570, 159586, 232811, 340053, 497156, 727324, 1064569, 1558747, 2282918, 3344154, 4899383, 7178593, 10518844, 15414124, 22588409

Offset

1,1

Comments

Column 6 of A224606.

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*(1045 - 3286*x + 3780*x^2 - 2958*x^3 + 2847*x^4 - 1851*x^5 + 414*x^6 + 4*x^7) / ((1 - x)^3*(1 - x - x^3)). - Colin Barker, Sep 02 2018

Example

Some solutions for n=3:
..1..0..0..1..0..0..0..1....1..0..0..1..0..0..2..0....1..0..0..1..0..0..0..2
..1..0..0..1..0..0..0..1....1..0..0..1..0..0..1..0....1..0..0..1..0..0..0..0
..1..0..0..1..0..0..0..1....1..0..0..1..0..0..1..0....0..0..0..1..0..0..0..1
..1..0..0..1..0..0..0..1....1..0..0..1..0..0..1..0....0..0..0..1..0..0..0..1
..2..0..0..1..0..0..0..1....1..0..0..1..0..0..1..0....0..0..0..1..0..0..0..1

Crossrefs

Cf. A224606.

Sequence in context: A231112 A213811 A260205 * A045027 A345514 A345767

Adjacent sequences: A224601 A224602 A224603 * A224605 A224606 A224607

Keyword

nonn

Author

R. H. Hardin, Apr 11 2013

Status

approved