OFFSET
1,2
COMMENTS
Square array A(row,col) is read by downwards antidiagonals as: A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), A(0,3), A(1,2), A(2,1), A(3,0), ...
All the terms in the same row are either all divisible by 3, or none of them are.
Sequence A265345 is the main entry for this idea, please see further comment there.
LINKS
EXAMPLE
The top left corner of the array:
1, 2, 4, 8, 16, 64, 32, 184, 352, 704, 1408, ...
3, 6, 12, 24, 48, 192, 96, 552, 1056, 2112, 4224, ...
7, 10, 20, 40, 80, 160, 640, 320, 1600, 3520, 6080, ...
5, 22, 28, 56, 112, 224, 448, 1720, 824, 4936, 9856, ...
9, 18, 36, 72, 144, 576, 288, 1656, 3168, 6336, 12672, ...
21, 30, 60, 120, 240, 480, 1920, 960, 4800, 10560, 18240, ...
13, 26, 52, 208, 104, 520, 1144, 2072, 3712, 16120, 6968, ...
19, 14, 76, 136, 200, 256, 512, 1024, 6040, 3992, 15424, ...
25, 46, 68, 88, 496, 344, 1984, 1376, 5344, 7768, 15224, ...
11, 58, 44, 232, 424, 608, 736, 4384, 2936, 17536, 11744, ...
...
PROG
CROSSREFS
KEYWORD
AUTHOR
Antti Karttunen, Dec 18 2015
STATUS
approved