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A228477 Number of nX3 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or antidiagonally. 1
2, 4, 14, 41, 127, 386, 1181, 3605, 11013, 33635, 102734, 313780, 958385, 2927208, 8940618, 27307464, 83405606, 254747013, 778077691, 2376494562, 7258563605, 22169941573, 67713990833, 206819875427, 631693101322, 1929389878184 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A228482

Same recurrences as A228285 except in addition a smaller one for column 5

LINKS

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

FORMULA

a(n) = a(n-1) +5*a(n-2) +4*a(n-3) -a(n-5).

G.f.: -x*(-2-2*x+x^3) / ( (1+x)*(x^4-x^3-3*x^2-2*x+1) ). - R. J. Mathar, Aug 25 2013

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A279322 A152011 A000912 * A169982 A243323 A128750

Adjacent sequences:  A228474 A228475 A228476 * A228478 A228479 A228480

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 22 2013

STATUS

approved

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Last modified November 16 00:11 EST 2018. Contains 317252 sequences. (Running on oeis4.)