A222919 Number of n X 1 0..4 arrays with no three equal values in a row horizontally or vertically, and new values 0..4 introduced in row major order.

1, 2, 4, 12, 41, 158, 663, 2944, 13537, 63551, 301968, 1444795, 6940099, 33411718, 161058633, 776930015, 3749357128, 18098055047, 87370273487, 421820387606, 2036618058597, 9833358788859, 47478828272736, 229245800095323

Offset

1,2

Comments

Column 1 of A222924.

Links

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

Formula

Empirical: a(n) = 7*a(n-1) - 7*a(n-2) - 20*a(n-3) + 10*a(n-4) + 24*a(n-5) + 8*a(n-6) for n>8.

Empirical g.f.: x*(1 + x)*(1 - 6*x + 3*x^2 + 15*x^3 - 9*x^5 - 3*x^6) / ((1 - x - x^2)*(1 - 2*x - 2*x^2)*(1 - 4*x - 4*x^2)). - Colin Barker, Mar 16 2018

Example

All solutions for n=3:
..0....0....0....0
..1....1....1....0
..2....1....0....1

Crossrefs

Cf. A222924.

Sequence in context: A330679 A342225 A218144 * A264760 A090959 A244035

Adjacent sequences: A222916 A222917 A222918 * A222920 A222921 A222922

Keyword

nonn

Author

R. H. Hardin, Mar 09 2013

Status

approved