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A228261 Number of third differences of arrays of length 5 of numbers in 0..n. 1
31, 143, 319, 565, 881, 1267, 1723, 2249, 2845, 3511, 4247, 5053, 5929, 6875, 7891, 8977, 10133, 11359, 12655, 14021, 15457, 16963, 18539, 20185, 21901, 23687, 25543, 27469, 29465, 31531, 33667, 35873, 38149, 40495, 42911, 45397, 47953, 50579, 53275 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 35*n^2 + n + 1 for n>1.
Conjectures from Colin Barker, Sep 10 2018: (Start)
G.f.: x*(31 + 50*x - 17*x^2 + 6*x^3) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>4.
(End)
EXAMPLE
Some solutions for n=4:
..0...-6...-2...-9...-4...-3...-7...-3....9....8...-1....5...-3....8..-13...-2
.-2...-2....8....7...-4...-9...13....2....2..-10....8....3...-5...-6....3....0
CROSSREFS
Row 2 of A228260.
Sequence in context: A182916 A233303 A185521 * A185513 A234122 A142758
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 19 2013
STATUS
approved

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Last modified April 20 02:13 EDT 2024. Contains 371798 sequences. (Running on oeis4.)