A224689 Number of (n+4) X 11 0..1 matrices with each 5 X 5 subblock idempotent.

6713, 2591, 2862, 3214, 3540, 3819, 4572, 5723, 7181, 8868, 10729, 13235, 16781, 21671, 28131, 36332, 46916, 60920, 79685, 104778, 137937, 181542, 239010, 315099, 416134, 550178, 727674, 962482, 1273220, 1684831, 2230321, 2953139, 3910594

Offset

1,1

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) + 4*a(n-3) - a(n-4) + a(n-5) - 3*a(n-6) + 3*a(n-7) - a(n-8) for n>12.

Empirical g.f.: x*(6713 - 24261*x + 32776*x^2 - 19540*x^3 + 4205*x^4 - 6627*x^5 + 18090*x^6 - 15825*x^7 + 4297*x^8 + 120*x^9 + 44*x^10 + 5*x^11) / ((1 - x)^3*(1 - x + x^2)*(1 - x^2 - x^3)). - Colin Barker, Sep 03 2018

Example

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

Crossrefs

Column 7 of A224690.

Sequence in context: A239565 A234242 A252602 * A190292 A164972 A190129

Adjacent sequences: A224686 A224687 A224688 * A224690 A224691 A224692

Keyword

nonn

Author

R. H. Hardin, Apr 15 2013

Status

approved