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A224726 Number of (n+3) X 9 0..2 matrices with each 4 X 4 subblock idempotent. 1
5737, 4129, 4868, 5371, 5727, 7090, 9090, 11457, 14037, 17836, 23484, 31351, 41643, 55578, 74998, 102125, 139377, 190396, 260660, 357879, 492171, 677302, 932510, 1284753, 1771097, 2442380, 3368672, 4647011, 6411491, 8847050, 12208690 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..122

FORMULA

Empirical: a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) + 2*a(n-4) - 5*a(n-5) + 4*a(n-6) - a(n-7) - a(n-8) + 2*a(n-9) - a(n-10) for n>12.

Empirical g.f.: x*(5737 - 13082*x + 9692*x^2 - 2583*x^3 - 11385*x^4 + 21581*x^5 - 12409*x^6 + 2549*x^7 + 5641*x^8 - 8500*x^9 + 2710*x^10 + 37*x^11) / ((1 - x)^3*(1 + x)*(1 + x^2)*(1 - x - x^4)). - Colin Barker, Sep 04 2018

EXAMPLE

Some solutions for n=2:

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

..1..0..0..0..1..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..0..0..0..0..0..0

..1..0..0..0..1..0..0..0..1....1..0..0..0..0..0..0..0..0

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

CROSSREFS

Column 6 of A224728.

Sequence in context: A252422 A183647 A028547 * A043484 A163027 A069301

Adjacent sequences:  A224723 A224724 A224725 * A224727 A224728 A224729

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 16 2013

STATUS

approved

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Last modified January 25 11:23 EST 2022. Contains 350567 sequences. (Running on oeis4.)