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A204214 Number of length 6 nonnegative integer arrays starting and ending with 0 with adjacent elements differing by no more than n. 1
21, 120, 404, 1025, 2181, 4116, 7120, 11529, 17725, 26136, 37236, 51545, 69629, 92100, 119616, 152881, 192645, 239704, 294900, 359121, 433301, 518420, 615504, 725625, 849901, 989496, 1145620, 1319529, 1512525, 1725956, 1961216, 2219745 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 5 of A204213.

LINKS

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

FORMULA

Empirical: a(n) = (23/12)*n^4 + (37/6)*n^3 + (91/12)*n^2 + (13/3)*n + 1.

Conjectures from Colin Barker, Jun 06 2018: (Start)

G.f.: x*(21 + 15*x + 14*x^2 - 5*x^3 + x^4) / (1 - x)^5.

a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.

(End)

EXAMPLE

Some solutions for n=5:

..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

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

..1....4....2....2....3....2....2....6....1....5....8...10....8....2....3....5

..4....3....7....1....2....0....3....5....5....4....6...10....3....6....3....6

..2....4....5....3....4....3....0....5....2....5....3....5....4....2....4....3

..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

CROSSREFS

Cf. A204213.

Sequence in context: A079417 A267877 A183318 * A074088 A245031 A316713

Adjacent sequences:  A204211 A204212 A204213 * A204215 A204216 A204217

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 12 2012

STATUS

approved

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Last modified July 11 01:51 EDT 2020. Contains 335600 sequences. (Running on oeis4.)