A190095 Number of rhombuses on a (n+1)X7 grid

6, 26, 66, 130, 212, 312, 412, 527, 650, 782, 914, 1059, 1204, 1358, 1520, 1691, 1862, 2044, 2226, 2417, 2608, 2808, 3008, 3217, 3430, 3652, 3874, 4105, 4336, 4576, 4816, 5065, 5314, 5572, 5830, 6097, 6364, 6640, 6916, 7201, 7486, 7780, 8074, 8377, 8680

Offset

1,1

Comments

Column 6 of A190098

Links

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

Formula

Empirical: a(n) = 2*a(n-1) -2*a(n-3) +a(n-4) for n>27

Example

Some solutions for n=3
..0..1....0..6....0..4....0..2....1..5....0..4....0..2....0..1....0..4....1..1
..1..0....1..4....1..2....0..5....1..6....0..5....0..3....1..3....1..2....1..3
..2..1....3..3....2..4....3..5....2..6....1..5....1..3....3..2....3..1....3..3
..1..2....2..5....1..6....3..2....2..5....1..4....1..2....2..0....2..3....3..1

Crossrefs

Sequence in context: A327713 A136892 A254527 * A135036 A166796 A001701

Adjacent sequences: A190092 A190093 A190094 * A190096 A190097 A190098

Keyword

nonn

Author

R. H. Hardin May 04 2011

Status

approved