2
  1   10 rrrcwwgyyyrrrcwwgyyy
 11  100 nnncnngnnnnnncnngnnn
-------------------------------------------------------
From generations 1 to 10, positions 1,2,3,11,12,13 are constrained
to r, r='a' or 'g' and positions 8,9,10,18,19,20 to y, y='c' or 't',
positions 5,6,15,16 to w, w='a' or 't'. Positions 4,7,14,17 are fixed

From generation 11-100, only positions 4,7,14,17 are fixed.

No constraints after generations 100.

w='a' or 't'		s='c' or 'g'
r='a' or 'g'		y='c' or 't'
k='g' or 't'		m='a' or 'c'

b='c', 'g', or 't'	d='a', 'g', or 't'
h='a', 'c', or 't'	v='a', 'c', or 'g'

n='a', 'c', 'g', or 't'
