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A129393
Row sums of A129392.
1
1, 5, -15, 29, -23, -43, 225, -499, 601, 197, -2991, 8189, -12599, 5045, 35265, -125971, 236857, -206683, -327375, 1808861, -4117079, 5115797, 1120929, -23825971, 66994201, -105678715, 49059345, 275536829, -1022847863, 1966396277, -1807797375, -2442192979, 14557768441
OFFSET
0,2
COMMENTS
Also a diagonal close to the top of A129392.
FORMULA
Conjectures from Colin Barker, Oct 07 2015: (Start)
a(n) = -2*a(n-1) - a(n-2) + 4*a(n-3) for n>2.
G.f.: (4*x^2-7*x-1) / ((x-1)*(4*x^2+3*x+1)).
(End)
MATHEMATICA
CoefficientList[Series[(4x^2-7x-1)/((x-1)(4x^2+3x+1)), {x, 0, 40}], x] (* or *) LinearRecurrence[{-2, -1, 4}, {1, 5, -15}, 40] (* Harvey P. Dale, Apr 01 2023 *)
CROSSREFS
Cf. A129392.
Sequence in context: A146060 A076843 A285406 * A268581 A298025 A162525
KEYWORD
sign
AUTHOR
Jonas Wallgren, Apr 13 2007
EXTENSIONS
More terms from R. J. Mathar, Apr 30 2007
STATUS
approved