OFFSET
0,3
COMMENTS
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,1,0,0,-1)
FORMULA
a(n)=sum{k=0..floor(n/2), C(n-k, k)(-1)^k*sum{j=0..n-2k, C(j, n-2k-2j)3^(3j-n+2k)}}; a(n)=sum{k=0..n, A014027(n-k)C(2, k/2)(1+(-1)^k)/2}.
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Oct 30 2004
STATUS
approved