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A183899
Number of nondecreasing arrangements of n+3 numbers in 0..4 with each number being the sum mod 5 of three others.
1
1, 5, 66, 174, 329, 539, 815, 1169, 1614, 2164, 2834, 3640, 4599, 5729, 7049, 8579, 10340, 12354, 14644, 17234, 20149, 23415, 27059, 31109, 35594, 40544, 45990, 51964, 58499, 65629, 73389, 81815, 90944, 100814, 111464, 122934, 135265, 148499, 162679
OFFSET
1,2
COMMENTS
Column 4 of A183904.
LINKS
FORMULA
Empirical: a(n) = (1/24)*n^4 + (11/12)*n^3 + (179/24)*n^2 + (199/12)*n - 81 for n>3.
Conjectures from Colin Barker, Apr 05 2018: (Start)
G.f.: x*(1 + 51*x^2 - 116*x^3 + 74*x^4 - 2*x^5 - 5*x^6 - 2*x^7) / (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>8.
(End)
EXAMPLE
All solutions for n=2:
..0....0....0....0....0
..1....1....2....1....0
..3....2....3....1....0
..3....2....4....2....0
..4....4....4....3....0
CROSSREFS
Cf. A183904.
Sequence in context: A167536 A237887 A042491 * A263784 A263785 A263786
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 07 2011
STATUS
approved