let s={1+2+4+8+...}
then s-1={2+4+8+16+...}
and 2s={2+4+8+16+...}
by inspection, s-1=2s
which gives us s=-1

in conclusion, {1+2+4+8+...}=-1












the mistake is that{1+2+4+8+...}=infinity

and infinity-1=infinity, and infinity*2=infinity

but not all infinities are equal