A224727 Number of (n+3) X 10 0..2 matrices with each 4 X 4 subblock idempotent.

8117, 5711, 6540, 7132, 7575, 9090, 11268, 13821, 16593, 20653, 26657, 34977, 45825, 60486, 80897, 109371, 148429, 201881, 275470, 377256, 517816, 711541, 978561, 1347070, 1855835, 2558018, 3526907, 4863988, 6709510, 9256888, 12772821

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..100

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) - 2*a(n-3) + 4*a(n-4) - 3*a(n-5) + 2*a(n-7) - a(n-8) for n>10.

Empirical g.f.: x*(8117 - 18640*x + 5641*x^2 + 15168*x^3 - 21787*x^4 + 15216*x^5 + 4385*x^6 - 11795*x^7 + 3637*x^8 + 48*x^9) / ((1 - x)^3*(1 + x)*(1 - x - x^4)). - Colin Barker, Sep 04 2018

Example

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

Crossrefs

Column 7 of A224728.

Sequence in context: A258541 A031588 A145657 * A163045 A069368 A068758

Adjacent sequences: A224724 A224725 A224726 * A224728 A224729 A224730

Keyword

nonn

Author

R. H. Hardin, Apr 16 2013

Status

approved