A129393 Row sums of A129392.

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.

Links

Table of n, a(n) for n=0..32.

Index entries for linear recurrences with constant coefficients, signature (-2, -1, 4).

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

Adjacent sequences: A129390 A129391 A129392 * A129394 A129395 A129396

Keyword

sign

Author

Jonas Wallgren, Apr 13 2007

Extensions

More terms from R. J. Mathar, Apr 30 2007

Status

approved