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A189325 Number of nondecreasing arrangements of n+2 numbers in 0..8 with the last equal to 8 and each after the second equal to the sum of one or two of the preceding four. 1
13, 24, 49, 95, 179, 321, 548, 866, 1267, 1733, 2248, 2806, 3408, 4056, 4752, 5498, 6296, 7148, 8056, 9022, 10048, 11136, 12288, 13506, 14792, 16148, 17576, 19078, 20656, 22312, 24048, 25866, 27768, 29756, 31832, 33998, 36256, 38608, 41056, 43602 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 8 of A189326.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = (1/3)*n^3 + 10*n^2 + (587/3)*n - 1558 for n>10.

Empirical g.f.: x*(13 - 28*x + 31*x^2 - 9*x^3 + 10*x^4 + 3*x^5 + 7*x^6 - 21*x^7 - 14*x^8 - 10*x^9 + 2*x^10 + 10*x^11 + 7*x^12 + x^13) / (1 - x)^4. - Colin Barker, May 02 2018

EXAMPLE

Some solutions for n=3:

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

..4....4....6....3....6....8....3....4....5....4....4....4....7....5....4....4

..6....4....7....4....8....8....3....4....5....4....4....4....7....5....4....4

..8....4....7....4....8....8....5....8....8....5....8....4....8....5....4....6

..8....8....8....8....8....8....8....8....8....8....8....8....8....8....8....8

CROSSREFS

Cf. A189326.

Sequence in context: A335973 A190040 A081723 * A053080 A014357 A018991

Adjacent sequences:  A189322 A189323 A189324 * A189326 A189327 A189328

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 20 2011

STATUS

approved

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Last modified October 16 20:36 EDT 2021. Contains 348047 sequences. (Running on oeis4.)