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A250021 Number of length 7+5 0..n arrays with no six consecutive terms having the maximum of any three terms equal to the minimum of the remaining three terms 1
20, 9090, 651144, 16813550, 226419876, 1956551556, 12294501768, 60858118860, 250423174860, 889518620342, 2803153559712, 7998958658106, 20995150489196, 51312795029880, 117921264043248, 256830905369688, 533584576037604 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A250014

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..33

FORMULA

Empirical: a(n) = n^12 - (68/35)*n^11 + (11737/1260)*n^10 - (90763/7560)*n^9 + (29389/1008)*n^8 - (1819/63)*n^7 + (2363/72)*n^6 - (457/280)*n^5 - (31987/1008)*n^4 + (180149/3780)*n^3 - (2139/70)*n^2 + (1427/210)*n

EXAMPLE

Some solutions for n=2

..0....2....1....2....0....2....0....0....2....2....2....0....2....2....0....2

..0....1....2....2....0....0....2....0....2....0....1....0....2....1....2....0

..0....0....0....2....1....1....2....2....0....0....2....2....0....2....1....1

..2....0....1....0....2....1....1....0....0....2....2....1....0....0....0....2

..1....1....2....0....2....0....2....1....2....2....0....0....0....1....0....0

..2....0....2....1....2....0....0....2....1....0....0....2....1....2....1....0

..0....1....0....0....0....1....0....0....2....1....0....2....2....2....0....2

..0....2....0....2....1....0....2....0....2....2....2....1....2....0....2....2

..2....0....2....2....0....2....2....2....1....0....2....2....0....2....2....0

..2....0....1....0....2....2....1....0....1....2....1....0....0....0....0....2

..1....1....2....0....0....0....0....1....2....2....2....0....2....0....0....1

..2....0....2....2....2....2....2....2....0....0....0....0....1....2....2....1

CROSSREFS

Sequence in context: A013725 A307914 A293286 * A203308 A109122 A135420

Adjacent sequences:  A250018 A250019 A250020 * A250022 A250023 A250024

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 10 2014

STATUS

approved

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Last modified April 16 18:53 EDT 2021. Contains 343050 sequences. (Running on oeis4.)