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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A224599 Number of (n+2) X 3 0..2 matrices with each 3 X 3 subblock idempotent. 1
122, 178, 297, 416, 628, 1045, 1694, 2668, 4265, 6922, 11196, 18035, 29122, 47134, 76253, 123292, 199424, 322681, 522090, 844664, 1366621, 2211238, 3577832, 5788951, 9366638, 15155530, 24522129, 39677528, 64199500, 103876957, 168076406 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 1 of A224606.
LINKS
FORMULA
Empirical: a(n) = 3*a(n-1) -3*a(n-2) +2*a(n-3) -a(n-4) -a(n-5) +a(n-6) for n>7.
Empirical g.f.: x*(122 - 188*x + 129*x^2 - 185*x^3 + 37*x^4 + 115*x^5 - 36*x^6) / ((1 - x)^2*(1 + x^2)*(1 - x - x^2)). - Colin Barker, Sep 01 2018
EXAMPLE
Some solutions for n=3:
..1..1..0....1..0..1....0..1..0....0..0..0....1..0..0....1..0..0....0..0..1
..0..0..0....0..0..0....0..1..0....0..0..0....0..0..0....0..0..0....0..0..1
..0..0..0....0..0..0....0..1..0....0..0..0....0..0..0....0..1..1....0..0..1
..1..0..1....0..0..0....0..1..0....2..1..1....2..1..1....0..0..0....0..0..1
..1..0..1....2..1..1....0..2..0....0..0..0....0..0..0....0..1..1....0..0..1
CROSSREFS
Cf. A224606.
Sequence in context: A280733 A309760 A224606 * A207147 A222578 A105983
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 11 2013
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 24 01:53 EDT 2024. Contains 373661 sequences. (Running on oeis4.)