OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,7,0,0,8).
FORMULA
a(n)=sum{k=0..n, if (mod(k(n-2k), 3)=0, comb(n, k), 0) }; a(3n)=A001045(3n+1)-A001045(3n); a(3n+1)=A001045(3n+2), a(3n+2)=A001045(3n+3).
G.f.: (4x^4-5x^3+3x^2+x+1)/(-8x^6-7x^3+1).
G.f.: ( -1-x-3*x^2+5*x^3-4*x^4 ) / ( (2*x-1)*(1+x)*(4*x^2+2*x+1)*(x^2-x+1) ). - R. J. Mathar, Dec 10 2014
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Sep 14 2003
STATUS
approved