A299594 Number of n X 7 0..1 arrays with every element unequal to 0, 1 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

21, 26, 65, 250, 541, 1225, 2583, 5488, 11899, 25570, 54750, 117697, 252985, 543115, 1166472, 2505919, 5382274, 11560042, 24830445, 53333641, 114554095, 246050920, 528494067, 1135150426, 2438187262, 5236983073, 11248510665, 24160660963

Offset

1,1

Comments

Column 7 of A299595.

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +3*a(n-3) +a(n-4) -a(n-5) -a(n-6) for n>9.

Empirical g.f.: x*(21 + 5*x + 18*x^2 + 96*x^3 + 127*x^4 + 234*x^5 + 49*x^6 - 102*x^7 - 73*x^8) / ((1 + x^2 - x^3)*(1 - x - 2*x^2 - x^3)). - Colin Barker, Feb 15 2018

Example

Some solutions for n=5:
..0..0..0..1..0..0..0. .0..0..0..0..0..0..0. .0..0..0..0..1..0..0
..0..0..0..0..0..0..0. .0..0..0..0..0..0..0. .0..0..0..0..0..0..0
..0..0..0..0..0..0..0. .0..0..0..0..0..0..0. .1..0..0..0..0..0..1
..1..0..0..0..0..0..0. .0..0..0..0..0..0..0. .0..0..0..0..0..0..0
..0..0..0..0..0..1..0. .0..0..0..0..1..0..0. .0..0..0..0..0..0..0

Crossrefs

Cf. A299595.

Sequence in context: A035700 A134935 A344978 * A318544 A173836 A064507

Adjacent sequences: A299591 A299592 A299593 * A299595 A299596 A299597

Keyword

nonn

Author

R. H. Hardin, Feb 13 2018

Status

approved