%I #13 May 05 2024 10:41:26

%S 0,4,28,148,700,3124,13468,56788,235900,969844,3958108,16068628,

%T 64983100,262058164,1054609948,4237571668,17007682300,68202916084,

%U 273328224988,1094862581908,4384099373500,17550344631604,70243219939228,281098403995348,1124770188696700

%N a(n) = 4*(4^n-3^n).

%C Suggested by a discussion on the Sequence Fans Mailing List; the formula is due to Jaume Oliver Lafont.

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (7,-12)

%F a(n) = 4*A005061(n) = 7*a(n-1)-12*a(n-2). G.f.: 4*x/((4*x-1)*(3*x-1)). [_R. J. Mathar_, Mar 18 2009]

%F a(n) = A005061(n)*4. [_Omar E. Pol_, Mar 18 2009]

%Y Cf. A005061.

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_, Mar 18 2009