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A250386 Number of length n+3 0..7 arrays with no four consecutive terms having the maximum of any two terms equal to the minimum of the remaining two terms 1
3192, 21168, 141344, 944272, 6308960, 42158796, 281731072, 1882722300, 12581692558, 84080003928, 561883915314, 3754919165700, 25093116937722, 167690571894812, 1120631136647428, 7488877503016204, 50046161038946360 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A250387

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) +22*a(n-2) -46*a(n-3) +133*a(n-4) +616*a(n-5) -4201*a(n-6) -3646*a(n-7) +21341*a(n-8) -66632*a(n-9) -24894*a(n-10) +839903*a(n-11) -475399*a(n-12) -2431863*a(n-13) +8820646*a(n-14) -6093429*a(n-15) -52029372*a(n-16) +78800953*a(n-17) +60427131*a(n-18) -440849842*a(n-19) +475646104*a(n-20) +1126920187*a(n-21) -2461056791*a(n-22) +868584593*a(n-23) +6052348452*a(n-24) -10666379285*a(n-25) -2036000169*a(n-26) +21839852091*a(n-27) -28252527846*a(n-28) -11493718820*a(n-29) +60075332084*a(n-30) -34089181484*a(n-31) -34480114740*a(n-32) +75274463592*a(n-33) -15832208844*a(n-34) -47658620844*a(n-35) +21572342568*a(n-36) -12371339232*a(n-37) -5079648672*a(n-38) +22260620880*a(n-39) -916920000*a(n-40) -3811095360*a(n-41) +639187200*a(n-42) -1581638400*a(n-43) -93312000*a(n-44) +373248000*a(n-45)

EXAMPLE

Some solutions for n=3

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

..3....5....3....2....1....7....3....0....2....3....7....0....2....2....7....7

..1....7....0....2....4....3....2....5....3....4....3....0....5....3....1....7

..5....6....7....7....0....6....6....1....5....7....4....2....7....7....7....5

..5....7....0....5....3....5....1....4....6....5....6....3....1....7....4....2

..1....3....7....4....2....1....1....6....3....6....6....4....4....6....1....6

CROSSREFS

Sequence in context: A115932 A187936 A252367 * A069401 A225056 A306197

Adjacent sequences:  A250383 A250384 A250385 * A250387 A250388 A250389

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 20 2014

STATUS

approved

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Last modified December 11 07:44 EST 2019. Contains 329914 sequences. (Running on oeis4.)