OFFSET
0,3
COMMENTS
Row sums of Riordan array (1,x(1-11x)).
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1,-11).
FORMULA
a(n) = a(n-1)-11*a(n-2) ; a(0)=1, a(1)=1.
a(n) = Sum_{k=0..n} A109466(n,k)*11^(n-k).
From G. C. Greubel, Jan 31 2016: (Start)
G.f.: 1/(1-x+11*x^2).
E.g.f.: exp(x/2)*(cos(sqrt(43)*x/2) + (1/sqrt(43))*sin(sqrt(43)*x/2)).
(End)
MATHEMATICA
LinearRecurrence[{1, -11}, {1, 1}, 30] (* Harvey P. Dale, Jan 07 2016 *)
PROG
(Sage) [lucas_number1(n, 1, 11) for n in range(1, 26)] # Zerinvary Lajos, Apr 22 2009
(PARI) Vec(1/(1-x*(1-11*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012
(Magma) [n le 2 select 1 else Self(n-1)-11*Self(n-2): n in [1..30]]; // Vincenzo Librandi, Jan 31 2016
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Philippe Deléham, Oct 27 2008
STATUS
approved