%I #14 Aug 04 2021 16:18:20
%S 0,1,20,350,6000,102500,1750000,29875000,510000000,8706250000,
%T 148625000000,2537187500000,43312500000000,739390625000000,
%U 12622187500000000,215474218750000000,3678375000000000000
%N Third binomial transform of Pell(3*n)/Pell(3).
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (20,-50).
%F G.f.: x/(1-20*x+50*x^2);
%F a(n) = ((10 + 5*sqrt(2))^n - (10 - 5*sqrt(2))^n)/(10*sqrt(2)).
%t LinearRecurrence[{20,-50},{0,1},30] (* _Harvey P. Dale_, Aug 04 2021 *)
%Y Cf. A000129, A041085.
%K easy,nonn
%O 0,3
%A _Paul Barry_, Mar 26 2004