A184000 Number of (n+1) X 7 0..2 arrays with all 2 X 2 subblock sums the same.

5175, 6417, 8415, 12525, 19935, 35565, 66591, 134853, 282735, 628557, 1444815, 3494805, 8731935, 22771005, 60933951, 168205893, 472111695, 1351666797, 3905565615, 11418586485, 33538635135, 99183404445, 293959431711

Offset

1,1

Comments

Column 6 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.: 3*x*(1725 - 8211*x - 10029*x^2 + 90845*x^3 - 36690*x^4 - 300280*x^5 + 263292*x^6 + 304884*x^7 - 328536*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 7:
..2..2..0..0..2..0..1....0..1..2..2..2..1..2....1..0..0..1..2..2..1
..0..0..2..2..0..2..1....2..2..0..1..0..2..0....1..2..2..1..0..0..1
..2..2..0..0..2..0..1....0..1..2..2..2..1..2....1..0..0..1..2..2..1

Crossrefs

Cf. A184003.

Sequence in context: A249841 A247258 A107344 * A247259 A186900 A186847

Adjacent sequences: A183997 A183998 A183999 * A184001 A184002 A184003

Keyword

nonn

Author

R. H. Hardin, Jan 08 2011

Status

approved