A249890 Number of length 7+6 0..n arrays with no seven consecutive terms having the maximum of any three terms equal to the minimum of the remaining four terms.

35, 20942, 2027106, 67100334, 1111583581, 11450986236, 83742245992, 473488497480, 2192694269979, 8660886469382, 30052094475746, 93649537009470, 266568651310221, 702331289801020, 1730980486430688, 4025061896008000

Offset

1,1

Comments

Row 7 of A249883.

Links

R. H. Hardin, Table of n, a(n) for n = 1..20

Formula

Empirical: a(n) = n^13 - (10963/4620)*n^12 + (90131/7700)*n^11 - (265259/15120)*n^10 + (644381/15120)*n^9 - (442943/10080)*n^8 + (322067/6300)*n^7 + (1061/252)*n^6 - (62261/1008)*n^5 + (508283/6048)*n^4 - (1313561/37800)*n^3 - (21229/3080)*n^2 + (8746/1155)*n.

Example

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

Crossrefs

Cf. A249883.

Sequence in context: A215570 A271073 A271074 * A285388 A212926 A139473

Adjacent sequences: A249887 A249888 A249889 * A249891 A249892 A249893

Keyword

nonn

Author

R. H. Hardin, Nov 07 2014

Status

approved