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A215191 Number of arrays of 4 0..n integers with no sum of consecutive elements equal to a disjoint adjacent sum of an equal number of elements. 1
0, 18, 88, 276, 664, 1366, 2512, 4264, 6800, 10330, 15080, 21308, 29288, 39326, 51744, 66896, 85152, 106914, 132600, 162660, 197560, 237798, 283888, 336376, 395824, 462826, 537992, 621964, 715400, 818990, 933440, 1059488, 1197888, 1349426 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row 4 of A215190.

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) - 5*a(n-2) + 5*a(n-4) - 4*a(n-5) + a(n-6).

Conjectures from Colin Barker, Jul 22 2018: (Start)

G.f.: 2*x^2*(9 + 8*x + 7*x^2) / ((1 - x)^5*(1 + x)).

a(n) = n*(3*n^3 + n^2 - 1)/3 for n even.

a(n) = (3*n^4 + n^3 - n - 3)/3 for n odd.

(End)

EXAMPLE

Some solutions for n=6:

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

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

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

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

CROSSREFS

Cf. A215190.

Sequence in context: A126405 A250101 A141842 * A063788 A066854 A247901

Adjacent sequences:  A215188 A215189 A215190 * A215192 A215193 A215194

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 05 2012

STATUS

approved

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Last modified October 6 12:35 EDT 2022. Contains 357264 sequences. (Running on oeis4.)