A267784 Number of nX4 0..1 arrays with every repeated value in every row greater than or equal to, and in every column greater than, the previous repeated value.

15, 225, 1056, 5081, 14956, 44742, 102954, 238813, 472174, 935890, 1669256, 2973801, 4921484, 8116406, 12686802, 19733869, 29485150, 43804354, 63094592, 90326137, 126206748, 175240166, 238647082, 322974141, 430276638, 569730226

Offset

1,1

Comments

Column 4 of A267788.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +6*a(n-2) -14*a(n-3) -14*a(n-4) +42*a(n-5) +14*a(n-6) -70*a(n-7) +70*a(n-9) -14*a(n-10) -42*a(n-11) +14*a(n-12) +14*a(n-13) -6*a(n-14) -2*a(n-15) +a(n-16) for n>18

Example

Some solutions for n=4
..0..1..1..0....0..0..0..0....1..0..0..0....0..1..1..0....1..1..0..1
..1..0..0..1....0..0..1..0....0..1..1..1....1..0..0..1....0..0..0..0
..0..1..1..1....1..1..0..1....1..1..1..0....0..0..1..0....0..1..1..1
..1..0..1..0....1..1..1..1....0..0..0..0....0..1..1..1....1..1..1..1

Crossrefs

Cf. A267788.

Sequence in context: A207726 A207596 A208115 * A207700 A207905 A208036

Adjacent sequences: A267781 A267782 A267783 * A267785 A267786 A267787

Keyword

nonn

Author

R. H. Hardin, Jan 20 2016

Status

approved