OFFSET
0,2
COMMENTS
Diagonal sums of A113310.
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 2, -1).
FORMULA
a(n)=2a(n-2)-a(n-3); a(n)=sum{k=0..floor(n/2), sum{i=0..n-2k, (-1)^i*C(i+k-2, i)}}.
MATHEMATICA
LinearRecurrence[{0, 2, -1}, {1, 2, 3}, 50] (* Harvey P. Dale, May 19 2014 *)
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Oct 25 2005
STATUS
approved