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A249846 Number of length 2+4 0..n arrays with no five consecutive terms having the maximum of any two terms equal to the minimum of the remaining three terms. 1
10, 198, 1500, 6916, 23526, 65226, 156184, 335016, 659682, 1213102, 2109492, 3501420, 5587582, 8621298, 12919728, 18873808, 26958906, 37746198, 51914764, 70264404, 93729174, 123391642, 160497864, 206473080, 262938130, 331726590 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 2 of A249844.

LINKS

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

FORMULA

Empirical: a(n) = n^6 + (9/5)*n^5 + 3*n^4 + 3*n^3 + n^2 + (1/5)*n.

Conjectures from Colin Barker, Aug 18 2017: (Start)

G.f.: 2*x*(5 + 64*x + 162*x^2 + 112*x^3 + 17*x^4) / (1 - x)^7.

a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.

(End)

EXAMPLE

Some solutions for n=6

..4....5....1....0....5....0....1....6....5....3....6....5....0....5....1....5

..6....1....0....1....6....1....6....0....0....1....1....0....5....3....2....4

..5....3....4....0....3....5....3....3....2....5....6....4....2....5....0....1

..6....5....0....6....0....3....4....3....0....6....6....0....4....4....5....4

..6....0....1....4....0....0....2....0....2....5....2....4....1....3....3....2

..4....3....5....3....4....2....4....5....1....3....0....4....0....5....4....4

CROSSREFS

Sequence in context: A224298 A222499 A097127 * A211419 A001085 A079436

Adjacent sequences:  A249843 A249844 A249845 * A249847 A249848 A249849

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 07 2014

STATUS

approved

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Last modified February 22 05:58 EST 2018. Contains 299430 sequences. (Running on oeis4.)