|
| |
|
|
A129398
|
|
Pyramid P(h,x,y)=P(h,x,y-1)+P(h,x,y+1)+P(h,x-1,y)+P(h,x+1,y)+P(h-1,x,y), read level by level, x by x.
|
|
2
| |
|
|
1, 1, 1, 5, 1, 1, 1, 1, -3, 1, 1, -3, -7, -3, 1, 1, -3, 1, 1, 1, 1, 4, 1, 1, 3, 0, 3, 1, 1, 4, 0, -7, 0, 4, 1, 1, 3, 0, 3, 1, 1, 4, 1, 1
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,4
|
|
|
COMMENTS
| All face elements=1. For an element x on a level inside the pyramid
..b
.cxd
..e
with a above x, x=a+b+c+d+e. Every level of the pyramid is symmetric. Thus the top (h=0) of the pyramid is 1. The level h=1 is
..1
.1.5.1
..1
The level h=2 is
.....1
..1.-3..1
1.-3.-7.-3..1
..1.-3..1
.....1
The level h=3 is
........1
.....1..4..1
..1..3..0..3..1
1..4..0.-7..0..4..1
..1..3..0..3..1
.....1..4..1
........1
|
|
|
CROSSREFS
| This is a three-dimensional analogue of A129392.
Cf. A129392, A129399.
Sequence in context: A031261 A188796 A161685 * A109009 A060904 A135469
Adjacent sequences: A129395 A129396 A129397 * A129399 A129400 A129401
|
|
|
KEYWORD
| sign
|
|
|
AUTHOR
| Jonas Wallgren (jonwa(AT)ida.liu.se), Apr 13 2007
|
| |
|
|
