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A224562 Number of (n+3) X 5 0..1 matrices with each 4 X 4 subblock idempotent. 1
370, 340, 428, 517, 611, 775, 1044, 1383, 1808, 2373, 3190, 4323, 5868, 7946, 10825, 14809, 20317, 27872, 38285, 52646, 72495, 99863, 137615, 189693, 261595, 360821, 497771, 686759, 947616, 1307656, 1804613, 2490510, 3437232, 4743946, 6547576 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A224568.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 2*a(n-1) - a(n-2) + a(n-3) - 2*a(n-5) + a(n-6) - 2*a(n-7) + 2*a(n-8) + a(n-11) - a(n-12) for n>15.

Empirical g.f.: x*(370 - 400*x + 118*x^2 - 369*x^3 - 335*x^4 + 382*x^5 - 102*x^6 + 715*x^7 - 143*x^8 - 23*x^9 - 14*x^10 - 361*x^11 + 119*x^12 + 26*x^13 + 5*x^14) / ((1 - x)^3*(1 + x)*(1 + x^2)*(1 + x + x^2)*(1 - x - x^4)). - Colin Barker, Sep 01 2018

EXAMPLE

Some solutions for n=3:

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

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

..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0

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

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

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

CROSSREFS

Cf. A224568.

Sequence in context: A255202 A255194 A108772 * A276413 A161020 A102618

Adjacent sequences:  A224559 A224560 A224561 * A224563 A224564 A224565

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 10 2013

STATUS

approved

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Last modified November 29 06:32 EST 2021. Contains 349416 sequences. (Running on oeis4.)