OFFSET
0,4
COMMENTS
LINKS
FORMULA
G.f.: x*(1+x+3x^2+5x^3)/(1-x^4); e.g.f.: 2*cos(x) - sin(x) + exp(-x)/2 + 5*exp(x)/2 - 5; a(n) = 2*cos(Pi*n/2) - sin(Pi*n/2) + (-1)^n/2 + 5/2 - 5*0^n.
a(n) = a(n-4) for n > 4. - Elmo R. Oliveira, May 11 2024
MATHEMATICA
CoefficientList[Series[x (1+x+3x^2+5x^3)/(1-x^4), {x, 0, 150}], x] (* Harvey P. Dale, Mar 26 2011 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Dec 18 2003
STATUS
approved