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A228254 Number of third differences of arrays of length n+3 of numbers in 0..2. 1
17, 143, 621, 2059, 6305, 19171, 58025, 175099, 527345, 1586131, 4766585, 14316139, 42981185, 129009091, 387158345, 1161737179, 3485735825, 10458256051, 31376865305, 94134790219, 282412759265, 847255055011, 2541798719465 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) - 6*a(n-2) for n>5.
Conjectures from Colin Barker, Sep 10 2018: (Start)
G.f.: x*(17 + 58*x + 8*x^2 - 188*x^3 - 264*x^4) / ((1 - 2*x)*(1 - 3*x)).
a(n) = 3^(3+n) - 2^(3+n) for n>3.
(End)
EXAMPLE
Some solutions for n=4:
.-7...-4....3....4....3....1....1...-7....3....1....4...-3...-4...-2...-7...-1
..7....2....0...-6...-3....3....2....6....3....2...-2....4....0....3....7....2
.-4....2...-3....5....0...-5...-1...-1...-6...-4...-2...-3....3...-2...-3....0
..2...-4....3...-3....3....7...-1...-1....4....4....3....0...-4...-2...-2...-1
CROSSREFS
Column 2 of A228260.
Sequence in context: A157360 A142815 A222478 * A304207 A163038 A216422
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 19 2013
STATUS
approved

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Last modified March 5 06:14 EST 2024. Contains 370537 sequences. (Running on oeis4.)