A194935 Number of lower triangles of a 6 X 6 0..n array with no element differing from any of its horizontal or vertical neighbors by more than one.

2097152, 43337009, 136403494, 248381815, 364130672, 480403525, 596729942, 713059915, 829390016, 945720119, 1062050222, 1178380325, 1294710428, 1411040531, 1527370634, 1643700737, 1760030840, 1876360943, 1992691046

Offset

1,1

Comments

Row 6 of A194931.

Links

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

Formula

Empirical: a(n) = 116330103*n - 217580911 for n>8.

Empirical g.f.: x*(2097152 + 39142705*x + 51826628*x^2 + 18911836*x^3 + 3770536*x^4 + 523996*x^5 + 53564*x^6 + 3556*x^7 + 128*x^8 + 2*x^9) / (1 - x)^2. - Colin Barker, May 05 2018

Example

Some solutions for n=2:
..2............2............0............0............1............0
..1.0..........1.2..........0.0..........0.0..........1.0..........1.2
..0.0.0........2.2.2........1.1.0........1.0.1........0.0.1........1.1.0
..0.0.1.2......2.1.2.1......0.0.0.0......0.1.0.1......1.1.0.0......2.2.1.2
..1.1.0.1.1....1.0.1.1.2....1.1.0.1.1....1.1.0.1.2....0.0.1.1.1....1.2.1.2.2
..2.1.0.0.0.0..2.1.2.2.2.2..0.0.0.0.0.0..0.0.0.0.1.1..1.0.0.0.1.1..2.2.2.2.1.1

Crossrefs

Cf. A194931.

Sequence in context: A022537 A195236 A068345 * A016999 A017071 A017263

Adjacent sequences: A194932 A194933 A194934 * A194936 A194937 A194938

Keyword

nonn

Author

R. H. Hardin, Sep 05 2011

Status

approved