A184002 Number of (n+1) X 9 0..2 arrays with all 2 X 2 subblock sums the same.

35535, 40041, 47031, 61125, 85431, 134853, 227319, 418461, 799815, 1612581, 3338151, 7206765, 16031991, 37247253, 89664279, 225444381, 586169895, 1579364421, 4360148871, 12326941005, 35353745751, 102812027253, 301213506039

Offset

1,1

Comments

Column 8 of A184003.

Links

R. H. Hardin, Table of n, a(n) for n = 1..46

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.: 3*x*(11845 - 57723*x - 64405*x^2 + 637013*x^3 - 299778*x^4 - 2096536*x^5 + 1958172*x^6 + 2114964*x^7 - 2396952*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 9:
..1..2..0..1..1..0..0..2..0....0..0..2..1..1..2..2..1..0
..0..0..1..1..0..2..1..0..1....2..2..0..1..1..0..0..1..2
..1..2..0..1..1..0..0..2..0....0..0..2..1..1..2..2..1..0

Crossrefs

Cf. A184003.

Sequence in context: A250978 A282129 A203337 * A205741 A206673 A205517

Adjacent sequences: A183999 A184000 A184001 * A184003 A184004 A184005

Keyword

nonn

Author

R. H. Hardin, Jan 08 2011

Status

approved