A228457 Number of arrays of maxima of three adjacent elements of some length n+2 0..4 array.

5, 25, 95, 295, 821, 2227, 6254, 18394, 55285, 165563, 489488, 1433536, 4188613, 12268735, 36052642, 106118146, 312319987, 918413167, 2698818913, 7929048609, 23298823959, 68477103061, 201284983126, 591668573686, 1739085580405

Offset

1,1

Comments

Column 4 of A228461

Links

R. H. Hardin, Table of n, a(n) for n = 1..191

Formula

Empirical: a(n) = 5*a(n-1) -10*a(n-2) +10*a(n-3) +5*a(n-4) -9*a(n-5) +20*a(n-6) +8*a(n-7) +2*a(n-8) +14*a(n-9) +6*a(n-10) +2*a(n-11) +3*a(n-12) +a(n-13)

Example

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

Crossrefs

Sequence in context: A057255 A134140 A225011 * A213293 A203184 A073374

Adjacent sequences: A228454 A228455 A228456 * A228458 A228459 A228460

Keyword

nonn

Author

R. H. Hardin Aug 22 2013

Status

approved