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A228256 Number of third differences of arrays of length n+3 of numbers in 0..4. 1
33, 565, 6419, 53315, 315601, 1688101, 8717049, 44633821, 227363409, 1153594261, 5835080169, 29443836301, 148292923329, 745759583941, 3745977788889, 18798608421181, 94267920012849, 472439111692021, 2366593604971209 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..121

FORMULA

Empirical: a(n) = 9*a(n-1) - 20*a(n-2) for n>8.

Conjectures from Colin Barker, Sep 10 2018: (Start)

G.f.: x*(33 + 268*x + 1994*x^2 + 6844*x^3 - 35854*x^4 - 86008*x^5 - 163840*x^6 - 57600*x^7) / ((1 - 4*x)*(1 - 5*x)).

a(n) = 5^(3+n) - 4^(3+n) for n>6.

(End)

EXAMPLE

Some solutions for n=4:

.12..-10....2...-7....8...-5....2..-13...-7..-15...-6...-3....5....3....7....2

.-7....8....3....6...-2....1....0...13....4....9....0....4...-2...-3..-12....3

.-1...-6....1....1...-1...-3...-7..-12....1....0....9...-1...-6....2...12...-1

..4....8...-7...-1...-4...-2...10...12...-6...-2..-13...-3...10...-5...-6....5

CROSSREFS

Column 4 of A228260.

Sequence in context: A188357 A126923 A010985 * A197361 A282926 A172362

Adjacent sequences:  A228253 A228254 A228255 * A228257 A228258 A228259

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 19 2013

STATUS

approved

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Last modified December 3 22:32 EST 2021. Contains 349468 sequences. (Running on oeis4.)