Question 1086898

{{{1/72}}}, {{{1/36}}}, {{{1/18}}}, {{{1/9 }}}

this is a geometric sequence
if we first term  multiply by {{{2}}}, we will get second term

{{{(1/72)2=2/72=1/36}}}...do same with second term  to get third term

{{{(1/36)2=2/36=1/18}}}, 

{{{(1/18)2=2/18=1/9}}}

next fraction is:

{{{(1/9 )2=2/9}}}

{{{(2/9)2=4/9}}}

so, sequence is

{{{1/72}}}, {{{1/36}}}, {{{1/18}}}, {{{1/9}}},{{{ 2/9}}}, {{{4/9}}}, {{{8/9}}}, {{{16/9}}}, {{{32/9}}}, ...

general formula:

{{{a[n] = 2^(n - 4)/9 }}}