Below is a difference table.  The first
column consists of the 5 numbers in the 
sequence.  In all other columns each 
number in the difference between the 
number just left of it and the number 
just under the number just left of it.

  8    6    6  10  54 
 14   12   16  64
 26   28   80
 54  108  
162

So we put another 54 under the 54 and
add the number just to the left of it
and place the sum underneath the number
just left of it.  Do this all the way
to the left column until we have
extended the difference table so that
the first column has one more number:

  8    6    6   10  54 
 14   12   16   64  54
 26   28   80  118
 54  108  198
162  306
468

So by the method of the difference table,
the next term is 468.

General term:  


Edwin