A166766 Number of n X 4 1..2 arrays containing at least one of each value, and all equal values connected.

6, 56, 292, 1254, 4942, 18584, 67756, 241542, 846502, 2927816, 10023380, 34042358, 114900334, 385933816, 1291392908

Offset

1,1

Links

Table of n, a(n) for n=1..15.

Example

Some solutions for n=4
...1.1.1.1...2.2.1.1...2.2.2.2...1.1.2.2...2.2.2.2...2.1.1.1...2.2.2.2
...1.2.1.1...2.1.1.1...1.2.1.2...2.1.1.2...1.1.2.1...2.2.1.1...2.2.2.2
...1.2.1.2...2.1.1.1...1.2.1.1...2.1.2.2...1.1.1.1...2.2.1.1...1.2.2.1
...2.2.2.2...1.1.1.1...1.1.1.1...2.2.2.2...1.1.1.1...2.1.1.1...1.1.1.1
------
...2.2.2.2...2.2.2.2...2.2.1.1...1.1.2.1...2.1.1.1...1.1.1.1...1.1.2.2
...2.1.1.1...1.1.1.2...1.2.2.1...1.1.2.1...2.1.2.2...1.2.1.2...1.1.1.1
...1.1.1.1...1.1.2.2...1.2.1.1...1.1.1.1...2.1.2.2...1.2.2.2...1.1.1.1
...1.1.1.1...2.2.2.2...1.1.1.1...1.1.1.1...2.2.2.2...1.1.2.2...1.1.1.1

Crossrefs

Sequence in context: A345473 A053127 A068495 * A221401 A364471 A097126

Adjacent sequences: A166763 A166764 A166765 * A166767 A166768 A166769

Keyword

nonn

Author

R. H. Hardin, Oct 21 2009

Status

approved