A184469 1/6 the number of (n+2) X 3 0..2 arrays with each 3 X 3 subblock containing one of one value, four of another, and four of the last.

315, 1095, 3705, 12339, 45585, 161739, 559305, 2147931, 7836561, 27667251, 108488889, 401513355, 1432182465, 5674143555, 21145265865, 75792359259, 301775575185, 1128283339059, 4053433203225, 16177609637451, 60579025906401

Offset

1,1

Comments

Column 1 of A184477.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) + 96*a(n-3) - 288*a(n-4) - 2700*a(n-6) + 8100*a(n-7) + 23328*a(n-9) - 69984*a(n-10).

Empirical g.f.: 3*x*(105 + 50*x + 140*x^2 - 9672*x^3 - 1944*x^4 - 5112*x^5 + 269028*x^6 + 17496*x^7 + 42768*x^8 - 2332800*x^9) / ((1 - 3*x)*(1 - 18*x^3)*(1 - 24*x^3)*(1 - 54*x^3)). - Colin Barker, Apr 12 2018

Example

Some solutions with a(1,1)=0 for 4 X 3:
..0..2..2....0..1..2....0..2..0....0..0..2....0..1..2....0..1..2....0..2..1
..2..0..1....1..2..1....0..2..0....2..0..2....1..2..1....0..2..0....1..1..2
..0..2..0....2..1..2....2..1..2....2..1..0....2..1..2....2..2..0....1..2..2
..0..2..2....2..0..1....0..2..0....0..0..2....1..0..2....0..1..2....2..0..1

Crossrefs

Cf. A184477.

Sequence in context: A341358 A087415 A184477 * A088010 A145753 A184468

Adjacent sequences: A184466 A184467 A184468 * A184470 A184471 A184472

Keyword

nonn

Author

R. H. Hardin, Jan 15 2011

Status

approved