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A241621 Number of length 6+2 0..n arrays with no consecutive three elements summing to more than n. 1
28, 287, 1730, 7483, 25774, 75180, 193194, 449295, 963886, 1934647, 3672032, 6645821, 11544820, 19351984, 31437420, 49671909, 76563768, 115422055, 170549302, 247467143, 353178386, 496469260, 688255750, 941978115, 1274047866 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = (13/2880)*n^8 + (13/180)*n^7 + (145/288)*n^6 + (719/360)*n^5 + (14197/2880)*n^4 + (2789/360)*n^3 + (121/16)*n^2 + (251/60)*n + 1.

Conjectures from Colin Barker, Oct 30 2018: (Start)

G.f.: x*(28 + 35*x + 155*x^2 - 107*x^3 + 127*x^4 - 84*x^5 + 36*x^6 - 9*x^7 + x^8) / (1 - x)^9.

a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>9.

(End)

EXAMPLE

Some solutions for n=5:

..2....4....0....0....2....1....1....0....0....0....1....1....1....2....0....0

..1....0....3....3....2....3....1....3....3....2....3....2....3....0....0....2

..0....0....1....1....1....0....0....1....1....0....0....1....0....2....4....0

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

..0....0....3....2....0....1....0....0....2....2....0....0....0....1....1....2

..1....0....0....0....1....1....0....0....0....3....0....0....1....0....0....1

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

..1....2....2....0....1....1....0....2....1....2....1....0....1....0....4....0

CROSSREFS

Row 6 of A241619.

Sequence in context: A250649 A107418 A183484 * A027781 A219626 A126662

Adjacent sequences:  A241618 A241619 A241620 * A241622 A241623 A241624

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 26 2014

STATUS

approved

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Last modified February 26 05:51 EST 2020. Contains 332277 sequences. (Running on oeis4.)