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A184065 Number of (n+1) X 4 binary arrays with rows and columns in nondecreasing order and with no 2 X 2 subblock sum differing from a horizontal or vertical neighbor subblock sum by more than one. 1
20, 36, 130, 382, 924, 1884, 3463, 5800, 9065, 13397, 18940, 25837, 34232, 44269, 56092, 69845, 85672, 103717, 124124, 147037, 172600, 200957, 232252, 266629, 304232, 345205, 389692, 437837, 489784, 545677, 605660, 669877, 738472, 811589 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A184071.

LINKS

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

FORMULA

Conjectures from Colin Barker, Apr 11 2018: (Start)

G.f.: x*(20 - 44*x + 106*x^2 - 2*x^3 + 52*x^4 - 4*x^5 + 73*x^6 - 62*x^7 + 31*x^8 - 31*x^9 + 5*x^10 - x^11 + x^12) / (1 - x)^4.

a(n) = 757 + 14*n - 115*n^2 + 24*n^3 for n>9.

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>13.

(End)

EXAMPLE

Some solutions for 3 X 4:

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

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

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

...

...2..3..4.......2..2..2.......1..2..2.......1..2..2.......1..2..3...

...3..3..4.......2..1..2.......2..3..3.......2..3..2.......2..1..2...

CROSSREFS

Cf. A184071.

Sequence in context: A174628 A316098 A308664 * A259734 A294736 A217427

Adjacent sequences:  A184062 A184063 A184064 * A184066 A184067 A184068

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 09 2011

STATUS

approved

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Last modified December 1 12:50 EST 2020. Contains 338833 sequences. (Running on oeis4.)