OFFSET
1,2
COMMENTS
More generally for any n>=floor((m+1)/2) the trace of M(n)^(-m) = binomial(2*m,m)*n-2^(2*m-1)+binomial(2*m-1,m).
LINKS
S. Barbero, Dickson Polynomials, Chebyshev Polynomials, and Some Conjectures of Jeffery, Journal of Integer Sequences, 17 (2014), #14.3.8
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(1)=1 then a(n)=70n-93.
(Conjecture) G.f.: F(x)=x*(1+45*x+24*x^2)/(1-x)^2. - L. Edson Jeffery, Jan 21 2012
(Conjecture) a(n)=2*a(n-1)-a(n-2), n>1, a(1)=1, a(2)=47. - L. Edson Jeffery, Jan 21 2012
PROG
(PARI) a(n)=if(n<2, 1, 70*n-93)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Benoit Cloitre, Feb 09 2006
STATUS
approved