A152167 a(n)=-a(n-1)+3*a(n-2), n>1 ; a(0)=1, a(1)=-3 .

1, -3, 6, -15, 33, -78, 177, -411, 942, -2175, 5001, -11526, 26529, -61107, 140694, -324015, 746097, -1718142, 3956433, -9110859, 20980158, -48312735, 111253209, -256191414, 589951041, -1358525283, 3128378406, -7203954255, 16589089473

Offset: 0

Author

Philippe Deléham, Nov 27 2008

Keywords

• sign
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (-1,3).

Crossrefs

Cf. A105476, A147703.

Programs

Mathematica

LinearRecurrence[{-1,3},{1,-3},30] (* Harvey P. Dale, Dec 24 2013 *)

PARI

Vec((1-2*x)/(1+x-3*x^2)+O(x^99)) \\ Charles R Greathouse IV, Jan 11 2012

Formula

G.f.: (1-2*x)/(1+x-3*x^2).

a(n) = (-1)^n*A105476(n+1).

a(n) = Sum{k=0..n} A147703(n,k)*(-4)^k.

Extensions

a(19) corrected by Charles R Greathouse IV, Jan 11 2012