A183999 Number of (n+1) X 6 0..2 arrays with all 2 X 2 subblock sums the same.

2025, 2691, 3793, 6111, 10449, 19935, 39697, 85431, 190305, 450111, 1098433, 2812551, 7386129, 20098095, 55623217, 157619511, 451006785, 1309524831, 3821415073, 11250418791, 33202564209, 98511527055, 292616203537

Offset

1,1

Comments

Column 5 of A184003.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) - 60*a(n-3) + 85*a(n-4) + 150*a(n-5) - 360*a(n-6) + 396*a(n-8) - 216*a(n-9).

Empirical g.f.: x*(2025 - 9459*x - 12353*x^2 + 104853*x^3 - 36882*x^4 - 347664*x^5 + 289692*x^6 + 354564*x^7 - 367416*x^8) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)). - Colin Barker, Apr 09 2018

Example

Some solutions for 3 X 6:
..2..0..1..1..1..0....0..1..0..1..0..1....0..2..2..1..0..1....0..2..0..1..1..2
..0..2..1..1..1..2....2..2..2..2..2..2....2..1..0..2..2..2....2..1..2..2..1..1
..2..0..1..1..1..0....1..0..1..0..1..0....0..2..2..1..0..1....1..1..1..0..2..1

Crossrefs

Cf. A184003.

Sequence in context: A156855 A306870 A126172 * A360216 A250811 A350869

Adjacent sequences: A183996 A183997 A183998 * A184000 A184001 A184002

Keyword

nonn

Author

R. H. Hardin, Jan 08 2011

Status

approved