1+1

Plot[Sin[x], {x,0, 2π}]

Manipulate[Plot[Sin[a x], {x,0, 2π}],
{a,1,2}
]

a[n_] := (-1)^n/Log[n + 2]

Manipulate[s = 0; k0 = 0; k1 = 0;
ArrayPlot[Partition[Table[
If[s < w,
++k0; s += a[2 k0]; 0,
++k1; s += a[2 k1 - 1]; 1
],{1024}], 32]],
{w, -5, 5}
]