A093144 Third binomial transform of Pell(3*n)/Pell(3).

0, 1, 20, 350, 6000, 102500, 1750000, 29875000, 510000000, 8706250000, 148625000000, 2537187500000, 43312500000000, 739390625000000, 12622187500000000, 215474218750000000, 3678375000000000000

Offset: 0

Author

Paul Barry, Mar 26 2004

Keywords

• easy
• nonn

Links

• Index entries for linear recurrences with constant coefficients, signature (20,-50).

Crossrefs

Cf. A000129, A041085.

Programs

Mathematica

LinearRecurrence[{20,-50},{0,1},30] (* Harvey P. Dale, Aug 04 2021 *)

Formula

G.f.: x/(1-20*x+50*x^2);

a(n) = ((10 + 5*sqrt(2))^n - (10 - 5*sqrt(2))^n)/(10*sqrt(2)).