A211557 Number of nonnegative integer arrays of length n+3 with new values 0 upwards introduced in order, and containing the value 3

1, 11, 81, 512, 3046, 17866, 106133, 649045, 4125023, 27378716, 190102160, 1380567060, 10472967693, 82843346443, 682012236077, 5832548494812, 51723577104638, 474868072764550, 4506710508270721, 44151990164554541

Offset

1,2

Comments

Column 4 of A211561

Links

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

Formula

Empirical: a(n) = sum{j in 4..n+3}stirling2(n+3,j)

Example

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

Crossrefs

Sequence in context: A252817 A210064 A323223 * A333061 A055429 A227556

Adjacent sequences: A211554 A211555 A211556 * A211558 A211559 A211560

Keyword

nonn

Author

R. H. Hardin Apr 15 2012

Status

approved