this is going to be useful
this allows coercion to bigint
get the sum stuff going
we're doing modular arithmetic here
failing test to show we don't work for 64
the problem doesn't seem to be with getting the binary digits
or indeed with working out 64 to the 64
problem's reproducible with 80 though
the binary digits bit is fine though
ah-ha!
the value is wrong for 1000 though...