A224624 Number of (n+4) X 11 0..2 matrices with each 5 X 5 subblock idempotent.

54070, 31702, 36576, 39450, 41120, 42214, 50748, 64133, 80045, 97220, 115074, 141044, 179978, 234400, 305570, 394164, 508295, 660924, 867536, 1144876, 1510365, 1989537, 2620887, 3458395, 4572786, 6052206, 8010335, 10599348, 14025400

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..51

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*(54070 - 184578*x + 234188*x^2 - 132922*x^3 + 30038*x^4 - 54238*x^5 + 137896*x^6 - 114285*x^7 + 29507*x^8 + 264*x^9 + 52*x^10 + 5*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..0....1..0..0..0..0..1..0..0..0..0..1
..1..0..0..0..0..0..0..0..0..0..0....1..0..0..0..0..1..0..0..0..0..0
..0..0..0..0..0..0..0..0..0..0..0....1..0..0..0..0..1..0..0..0..0..2
..2..0..0..0..0..0..0..0..0..0..0....2..0..0..0..0..1..0..0..0..0..1
..2..0..0..0..0..0..0..0..0..0..1....0..0..0..0..0..1..0..0..0..0..1
..2..0..0..0..0..0..0..0..0..0..1....1..0..0..0..0..1..0..0..0..0..1

Crossrefs

Column 7 of A224625.

Sequence in context: A190472 A038564 A243362 * A202467 A224617 A224625

Adjacent sequences: A224621 A224622 A224623 * A224625 A224626 A224627

Keyword

nonn

Author

R. H. Hardin, Apr 12 2013

Status

approved