Comments on A065078
Wouter Meeussen (wouter.meeussen(AT)vandemoortele.com), Nov 09 2001 

Bottom plane of pyramid T[x,y,z=0] contains all 1's
They are considered all equivalent starting points.

x=
0         1

1       1    1

2     1    1    1

3   1    1    1    1
   /    /    /    /
y=0    1    2    3


First layer above this (so with z=1 in T[x,y,z=1]) is

x=
0         .

1       .    1

2     .    2    3

3   .    3    7    8
   /    /    /    /
y=0    1    2    3

The second layer above the bottom plane, z=2

x=
0         .

1       .    .

2     .    .    3

3   .    .    10    18
   /    /    /    /
y=0    1    2    3


and finaly, the top layer at z=3:

x=
0         .

1       .    .

2     .    .    .

3   .    .    .    18
   /    /    /    /
y=0    1    2    3



so, the 'top'-plane T[x,y,y] reads

1
1 (1)
1 (2) ((3))
1 (3) ((10)) (((18)))

where the number of brackets designates the z-level.