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A167554
The second left hand column of triangle A167552.
5
-2, -5, -7, -6, 0, 13, 35, 68, 114, 175, 253, 350, 468, 609, 775, 968, 1190, 1443, 1729, 2050, 2408, 2805, 3243, 3724, 4250, 4823, 5445, 6118, 6844, 7625, 8463, 9360, 10318, 11339, 12425, 13578, 14800, 16093, 17459, 18900, 20418
OFFSET
2,1
FORMULA
a(n) = (2*n^3 - 15*n^2 + 19*n - 6)/3!.
G.f.: (z^2 + 3*z - 2)/(z-1)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
a(n) - 3*a(n-1) + 3*a(n-2) - a(n-3) = 2*1.
MATHEMATICA
Table[(1/6)*(2*n^3 - 15*n^2 + 19*n - 6), {n, 2, 100}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {-2, -5, -7, -6}, 100] (* G. C. Greubel, Jun 15 2016 *)
CROSSREFS
Equals the second left hand column of A167552.
Other left hand columns are A005408, A167555, A168302 and A168303.
Sequence in context: A329283 A296168 A257963 * A202392 A290410 A078320
KEYWORD
easy,sign
AUTHOR
Johannes W. Meijer, Nov 10 2009
STATUS
approved