A195235 Number of lower triangles of a 5 X 5 0..n array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less.

32768, 127785, 237818, 348849, 459880, 570911, 681942, 792973, 904004, 1015035, 1126066, 1237097, 1348128, 1459159, 1570190, 1681221, 1792252, 1903283, 2014314, 2125345, 2236376, 2347407, 2458438, 2569469, 2680500, 2791531, 2902562, 3013593

Offset

1,1

Comments

Row 5 of A195232.

Links

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

Formula

Empirical: a(n) = 111031*n - 95275 for n>2.

Conjectures from Colin Barker, May 06 2018: (Start)

G.f.: x*(32768 + 62249*x + 15016*x^2 + 998*x^3) / (1 - x)^2.

a(n) = 2*a(n-1) - a(n-2) for n>4.

(End)

Example

Some solutions for n=4 with 0 and 4:
..0..........4..........4..........0..........4..........0..........0
..1.1........3.3........3.3........1.1........4.3........1.1........1.1
..2.2.2......2.2.2......2.2.2......1.2.2......3.3.2......2.2.2......2.2.2
..3.2.3.3....1.2.2.1....1.2.1.1....1.2.3.3....2.3.2.1....3.3.3.3....3.3.2.3
..2.3.2.3.4..1.2.2.1.0..2.1.1.0.1..2.2.3.3.4..3.2.2.1.0..2.3.4.4.4..4.3.3.3.4

Crossrefs

Cf. A195232.

Sequence in context: A232393 A217589 A069276 * A223335 A194934 A016997

Adjacent sequences: A195232 A195233 A195234 * A195236 A195237 A195238

Keyword

nonn

Author

R. H. Hardin, Sep 13 2011

Status

approved