A077836 Expansion of (1-x)/(1-3*x-3*x^2-3*x^3).

1, 2, 9, 36, 141, 558, 2205, 8712, 34425, 136026, 537489, 2123820, 8392005, 33159942, 131027301, 517737744, 2045774961, 8083620018, 31941398169, 126212379444, 498712192893, 1970597911518, 7786567451565, 30767632667928, 121574394093033, 480385782637578

Offset

0,2

Links

Table of n, a(n) for n=0..25.

Index entries for linear recurrences with constant coefficients, signature (3, 3, 3).

Formula

a(0)=1, a(1)=2, a(2)=9, a(n)=3*a(n-1)+3*a(n-2)+3*a(n-3). - Harvey P. Dale, Dec 15 2013

Mathematica

CoefficientList[Series[(1-x)/(1-3*x-3*x^2-3*x^3), {x, 0, 30}], x] (* or *) LinearRecurrence[{3, 3, 3}, {1, 2, 9}, 30] (* Harvey P. Dale, Dec 15 2013 *)

Crossrefs

Sequence in context: A007946 A135593 A027995 * A003125 A055841 A037521

Adjacent sequences: A077833 A077834 A077835 * A077837 A077838 A077839

Keyword

nonn

Author

N. J. A. Sloane, Nov 17 2002

Status

approved