A224621 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A224621

Number of (n+4) X 8 0..2 matrices with each 5 X 5 subblock idempotent.

32029, 22081, 26624, 29254, 30723, 31623, 39450, 51956, 66929, 83137, 100012, 124474, 161207, 212671, 280106, 364172, 472461, 617237, 813236, 1076422, 1423431, 1878479, 2478058, 3273384, 4331649, 5736669, 7596488, 10055630, 13309847

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 4 of A224625.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..40

FORMULA

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) - 2*a(n-3) + 3*a(n-4) - 2*a(n-6) + 2*a(n-8) - a(n-9) for n>13.

Empirical g.f.: x*(32029 - 74006*x + 24439*x^2 + 57602*x^3 - 55716*x^4 - 15033*x^5 + 48721*x^6 + 14698*x^7 - 49772*x^8 + 16668*x^9 + 300*x^10 + 64*x^11 + 4*x^12) / ((1 - x)^3*(1 + x)*(1 - x + x^2)*(1 - x^2 - x^3)). - Colin Barker, Sep 02 2018

EXAMPLE

Some solutions for n=2:

..1..1..1..1..1..1..0..2....0..1..0..0..0..0..0..0....1..0..0..0..0..0..0..2

..0..0..0..0..0..0..0..0....0..1..0..0..0..0..0..2....1..0..0..0..0..0..0..2

..0..0..0..0..0..0..0..0....0..1..0..0..0..0..0..1....2..0..0..0..0..0..0..1

..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..1....2..0..0..0..0..0..0..1

..0..0..0..0..0..0..0..0....0..1..0..0..0..0..0..1....2..0..0..0..0..0..0..1

..1..1..0..2..1..1..1..1....0..1..0..0..0..0..0..1....1..0..0..0..0..0..0..1

CROSSREFS

Cf. A224625.

Sequence in context: A269318 A269319 A197114 * A231613 A054038 A156977

Adjacent sequences: A224618 A224619 A224620 * A224622 A224623 A224624

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 12 2013

STATUS

approved