OFFSET
0,5
COMMENTS
Arithmetic hexagon of E. Lucas.
REFERENCES
E. Lucas, Théorie des nombres, Albert Blanchard, Paris, 1958, Tome 1, p. 89.
LINKS
E. Lucas, Théorie des nombres, Gauthier-Villars, Paris 1891, Tome 1, p. 89.
FORMULA
EXAMPLE
Square array begins:
1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, ... row n=0
1, 2, 3, 4, 5, 5, 0, 0, 0, 0, 0, ... row n=1
1, 3, 6, 10, 15, 20, 20, 0, 0, 0, 0, ... row n=2
0, 3, 9, 19, 34, 54, 74, 74, 0, 0, 0, ... row n=3
0, 0, 9, 28, 62, 116, 190, 264, 264, 0, 0, ... row n=4
0, 0, 0, 28, 90, 206, 396, 660, 924, 924, 0, ... row n=5
...
Array, read by rows, with 0 omitted:
1, 1, 1, 1, 1
1, 2, 3, 4, 5, 5
1, 3, 6, 10, 15, 20, 20
3, 9, 19, 34, 54, 74, 74
9, 28, 62, 116, 190, 264, 264
28, 90, 206, 396, 660, 924, 924
90, 296, 692, 1352, 2276, 3200, 3200
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Philippe Deléham, Mar 14 2013
STATUS
approved