A166827 Number of nX2 1..5 arrays containing at least one of each value, all equal values connected, rows considered as a single number in nondecreasing order, and columns considered as a single number in nonincreasing order.

0, 0, 55, 478, 2167, 7125, 19234, 45351, 96802, 191358, 355785, 629068, 1066417, 1744171, 2765724, 4268605, 6432852, 9490828, 13738635, 19549290, 27387835, 37828561, 51574534, 69479619, 92573206, 122087850

Offset

1,3

Links

Table of n, a(n) for n=1..26.

Formula

Empirical: a(n)=(n^8+32*n^7+420*n^6+1862*n^5-4431*n^4-23002*n^3+59450*n^2-39372*n+5040)/5040

Example

Some solutions for n=4
...1.1...3.1...1.1...2.1...3.3...3.1...2.2...3.2...1.1...4.1...2.1...3.3...2.1
...2.2...3.5...2.1...2.2...3.3...3.2...3.2...3.4...2.1...4.2...3.3...4.2...2.4
...3.2...3.5...3.3...2.3...4.1...4.4...3.5...4.4...3.3...4.2...4.3...4.2...2.5
...5.4...4.2...5.4...5.4...5.2...5.4...4.1...5.1...4.5...5.3...5.3...5.1...3.3
------
...3.2...3.3...2.2...2.2...2.1...3.2...1.1...3.1...3.1...3.2...3.3...3.1...3.1
...3.4...4.2...3.1...3.1...2.3...5.1...3.3...4.2...3.5...3.3...4.1...3.1...3.2
...5.1...5.1...4.1...3.3...4.3...5.1...4.2...4.2...4.2...5.1...5.2...4.1...3.2
...5.5...5.5...5.5...5.4...4.5...5.4...5.2...5.2...4.4...5.4...5.2...5.2...5.4

Crossrefs

Sequence in context: A116060 A145054 A166839 * A266035 A241699 A262103

Adjacent sequences: A166824 A166825 A166826 * A166828 A166829 A166830

Keyword

nonn

Author

R. H. Hardin Oct 21 2009

Status

approved