A205340 Number of length n+1 nonnegative integer arrays starting and ending with 0 with adjacent elements unequal but differing by no more than 7

0, 7, 42, 441, 4424, 48335, 542850, 6285127, 74286702, 893407361, 10894937088, 134418087923, 1674757658798, 21042485711561, 266318361927208, 3392084001234202, 43447635519011920, 559277626577030221

Offset

1,2

Comments

Column 7 of A205341

Links

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

Example

Some solutions for n=5
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..4....4....5....7....2....5....6....1....2....6....4....4....2....7....4....4
..5....5...10....9....7...12....8....0....8....4....9...11....8....1....9....5
.11...12....4...11....0...14....9....1...10....8....3....4...13....5....7....0
..6....6....5....5....6....7....4....4....4....7....7....5....7....2....1....4
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

Crossrefs

Sequence in context: A174224 A278571 A133669 * A304953 A293850 A202862

Adjacent sequences: A205337 A205338 A205339 * A205341 A205342 A205343

Keyword

nonn

Author

R. H. Hardin Jan 26 2012

Status

approved