

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
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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(n1)  6*a(n2) + 4*a(n3)  a(n4) 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



