|
%I #15 May 30 2023 17:23:02
%S 1,2,2,2,4,6,10,20,38,74,148,294,586,1172,2342,4682,9364,18726,37450,
%T 74900,149798,299594,599188,1198374,2396746,4793492,9586982,19173962,
%U 38347924,76695846,153391690,306783380,613566758,1227133514,2454267028,4908534054,9817068106
%N Expansion of g.f. (1 - 2*x^2 - 3*x^3)/((1 - x^3)*(1 - 2*x)).
%D P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 259.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,1,-2).
%F E.g.f.: exp(-x/2)*(exp(3*x/2)*(28 + 3*exp(x)) - 10*cos(sqrt(3)*x/2) + 2*sqrt(3)*sin(sqrt(3)*x/2))/21. - _Stefano Spezia_, May 30 2023
%t LinearRecurrence[{2,0,1,-2},{1,2,2,2},37] (* _Stefano Spezia_, May 30 2023 *)
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, Aug 21 2001
%E a(34)-a(36) from _Stefano Spezia_, May 30 2023
|
