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
FORMULA
a(n) = 924n-1586 with n>2, a(1)=1, a(2)=322.
a(n) = 2*a(n-1)-a(n-2) for n>4. G.f.: x*(1+320*x+543*x^2+60*x^3)/(1-x)^2. [Colin Barker, Mar 18 2012]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Benoit Cloitre, Feb 09 2006
STATUS
approved