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A184542 Number of (n+2) X 5 binary arrays with each 3 X 3 subblock having rows and columns in lexicographically nondecreasing order. 1
147, 340, 631, 1048, 1627, 2413, 3461, 4837, 6619, 8898, 11779, 15382, 19843, 25315, 31969, 39995, 49603, 61024, 74511, 90340, 108811, 130249, 155005, 183457, 216011, 253102, 295195, 342786, 396403, 456607, 523993, 599191, 682867, 775724, 878503 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A184548.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = (1/120)*n^5 + (5/24)*n^4 + (49/24)*n^3 + (739/24)*n^2 + (1659/20)*n + 31.

Conjectures from Colin Barker, Apr 13 2018: (Start)

G.f.: x*(147 - 542*x + 796*x^2 - 578*x^3 + 209*x^4 - 31*x^5) / (1 - x)^6.

a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>5.

(End)

EXAMPLE

Some solutions for 4 X 5:

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

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

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

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

CROSSREFS

Cf. A184548.

Sequence in context: A259288 A325608 A255103 * A162701 A063701 A261939

Adjacent sequences:  A184539 A184540 A184541 * A184543 A184544 A184545

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 16 2011

STATUS

approved

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Last modified April 10 11:15 EDT 2021. Contains 342845 sequences. (Running on oeis4.)