A211842 Number of nonnegative integer arrays of length n+3 with new values 0 upwards introduced in order, no three adjacent elements all unequal, and containing the value 2.

1, 5, 19, 63, 196, 588, 1731, 5049, 14689, 42809, 125364, 369678, 1099339, 3300091, 10006487, 30658799, 94932890, 297079702, 939477265, 3001846219, 9689289277, 31586215805, 103968208826, 345457027212, 1158435912189, 3919502591649

Offset

1,2

Comments

Column 1 of A211849.

Links

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

Example

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

Crossrefs

Cf. A211849.

Sequence in context: A003296 A053545 A049612 * A304134 A318946 A229239

Adjacent sequences: A211839 A211840 A211841 * A211843 A211844 A211845

Keyword

nonn

Author

R. H. Hardin Apr 22 2012

Status

approved