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A224622 Number of (n+4) X 9 0..2 matrices with each 5 X 5 subblock idempotent. 1
39001, 23453, 28058, 30723, 32204, 33115, 41120, 53862, 69089, 85561, 102702, 127605, 165006, 217389, 285998, 371501, 481659, 628969, 828412, 1096213, 1449265, 1912222, 2522235, 3331436, 4408182, 5837723, 7729963, 10231957, 13542892 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A224625.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..53

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*(39001 - 132551*x + 168252*x^2 - 96795*x^3 + 22849*x^4 - 39143*x^5 + 100600*x^6 - 84723*x^7 + 22198*x^8 + 256*x^9 + 50*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..1..0..0..0..0..0..0..1

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

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

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

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

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

CROSSREFS

Cf. A224625.

Sequence in context: A206597 A088237 A031644 * A233955 A250515 A031667

Adjacent sequences:  A224619 A224620 A224621 * A224623 A224624 A224625

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 12 2013

STATUS

approved

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Last modified December 5 06:52 EST 2021. Contains 349543 sequences. (Running on oeis4.)