
a[n_,k_]:=Mod[n,4 k]-(2 k +1)

b[n_,k_]:=If[n<4 k,1,0]

c[n_,k_]:=Abs[a[n,k]]+Abs[b[n,k]]

d[n_]:=Table[c[n,k],{k,1,n/4}]
