[seqfan] More fractal triangles (with primes)

[Eric Angelini]

Hello SeqFans,
Erase from T all pairs of integer [a(i), a(i+1)] that are prime 
or non-prime --like (2,3) or (4,6)-- and you'll get T back.

T = 
1,2,3,4,6,2,8,9,3,4,5,7,6,2,8,11,13,9,3,4,5,10,12,7,6,2,8,11,14,15,13,9,3,4,5,10,17,19,12,7,6,2,8,11,14,23,29,15,13,9,3,4,5,10,17,16,18,19,12,7,6,2,8,11,14,23,20,22,29,15,13,9,3,4,5,10,17,16,31,37,18,19,12,7,6,2,8,11,14,23,20,41,43,...

The generating triangles [after a(1)=1] are:

1            2                                3,4
           6,2,8                            9,3,4,5
         7,6,2,8,11                      13,9,3,4,5,10
      12,7,6,2,8,11,14                15,13,9,3,4,5,10,17
   19,12,7,6,2,8,11,14,23          29,15,13,9,3,4,5,10,17,16
18,19,12,7,6,2,8,11,14,23,20    22,29,15,13,9,3,4,5,10,17,16,31
            ...                               ...

Read horizontally, line after line, to see T.
Best,
É.