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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 January 20 03:32 EST 2019. Contains 319323 sequences. (Running on oeis4.)