A009025 Expansion of e.g.f.: cos(log(1+x))/cos(x).

1, 0, 0, 3, -11, 70, -354, 2415, -15763, 125172, -1002604, 9222455, -86960631, 905535618, -9647654054, 109599211995, -1245410413895, 14255558592040, -147402624694104, 1100681059753035, 7361694753788285, -667740119513804610

Offset

0,4

Links

G. C. Greubel, Table of n, a(n) for n = 0..250

Mathematica

With[{nn=30}, CoefficientList[Series[Cos[Log[1+x]]/Cos[x], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Dec 18 2011 *)

Prog

(PARI) x='x+O('x^30); Vec(serlaplace( cos(log(1+x))/cos(x) )) \\ G. C. Greubel, Jul 22 2018
(Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(Cos(Log(1+x))/Cos(x))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Jul 22 2018

Crossrefs

Sequence in context: A342057 A018193 A121945 * A009103 A018192 A056665

Adjacent sequences: A009022 A009023 A009024 * A009026 A009027 A009028

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Definition clarified by Harvey P. Dale, Aug 15 2022

Status

approved