OFFSET
1,3
COMMENTS
The number of signatures on each row is 1 2 5 14 42 132 ... cf. A000108.
REFERENCES
G. E. Andrews and K. Eriksson, Integer Partitions, Cambridge Univ. Press, 2004. page 22 Exer. 33.
EXAMPLE
The irregular array begins
1
1 2
1 2 4 6 12
1 2 4 6 8 12 24 30 36 60 72 120 180 360
CROSSREFS
KEYWORD
easy,nonn,tabf
AUTHOR
Alford Arnold, Jan 12 2008
STATUS
approved