OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,1,-1).
FORMULA
a(n) = floor(n/5)+floor(2n/5)+floor(3n/5)+floor(4n/5).
G.f.: 2*x^2*(1+x+x^2+2*x^3) / ( (x^4+x^3+x^2+x+1)*(x-1)^2 ). - R. J. Mathar, Mar 08 2011
MATHEMATICA
Table[Floor[n/5]+Floor[2n/5]+Floor[3n/5]+Floor[4n/5], {n, 0, 120}]
Table[Total[Floor/@((Range[4]n)/5)], {n, 0, 80}] (* or *) LinearRecurrence[ {1, 0, 0, 0, 1, -1}, {0, 0, 2, 4, 6, 10}, 80] (* Harvey P. Dale, Oct 19 2018 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Mar 08 2011
STATUS
approved