OFFSET
0,5
COMMENTS
Binomial transform has g.f. 1/(1-x+x^3) (A050935(n+2)).
LINKS
Index entries for linear recurrences with constant coefficients, signature (-2,-1,-1).
FORMULA
a(n)=-2a(n-1)-a(n-2)-a(n-3); a(n)=sum{j=0..n, sum{k=0..floor(j/3), C(n, j)(-1)^(n-j)C(j-2k, k)(-1)^k}}.
a(n)=(-1)^n*A005314(n-2). [From R. J. Mathar, Nov 26 2008]
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Oct 20 2004
STATUS
approved