OFFSET
1,2
FORMULA
a(r, s) = 3^(r-1)*2^(s-1).
EXAMPLE
In the following square array numbers are entered like this a(1,1), a(1,2), a(2,1), a(3,1), a(2,2), a(1,3), a(1,4), a(2,3), a(3,2), a(4,1), a(5,1), a(4,2),... such that every entry is the geometric mean of the two diametrically opposite neighbors (wherever a pair exists).
1 2 4 8 16 32 64...
3 6 12 24 48 96 192...
9 18 36 72 144 288 576...
27 54 108 216 432 864 1728...
...
Sequence contains numbers as they are entered.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Amarnath Murthy, Apr 10 2003
STATUS
approved