A224623 Number of (n+4) X 10 0..2 matrices with each 5 X 5 subblock idempotent.

43489, 24252, 28949, 31623, 33115, 34032, 42214, 55189, 70669, 87402, 104808, 130151, 168223, 221528, 291318, 378265, 490305, 640166, 843080, 1115531, 1474675, 1945604, 2566138, 3389329, 4484713, 5938982, 7863920, 10409131, 13777271

Offset

1,1

Comments

Column 6 of A224625.

Links

R. H. Hardin, Table of n, a(n) for n = 1..38

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*(43489 - 149704*x + 192875*x^2 - 112617*x^3 + 26798*x^4 - 43723*x^5 + 113448*x^6 - 96972*x^7 + 26141*x^8 + 195*x^9 + 65*x^10 + 4*x^11) / ((1 - x)^3*(1 - x + x^2)*(1 - x^2 - x^3)). - Colin Barker, Sep 02 2018

Example

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

Crossrefs

Cf. A224625.

Sequence in context: A184382 A126771 A103875 * A210331 A233690 A205923

Adjacent sequences: A224620 A224621 A224622 * A224624 A224625 A224626

Keyword

nonn

Author

R. H. Hardin, Apr 12 2013

Status

approved