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A136624
Irregular triangle read by rows: classify each numeric partition by sum of its parts and by the size of the staircase Ferrers board required to contain it. The triangle gives the number of partitions in each class, cf. A136102 and A136103.
3
1, 1, 2, 1, 2, 3, 3, 1, 2, 2, 6, 7, 6, 4, 1, 2, 2, 4, 8, 12, 15, 17, 14, 10, 5, 1
OFFSET
0,3
COMMENTS
Sequences A136102 and A136103 encode the numeric partitions by least prime signature and the Ferrers boards by 1 2 12 360 75600 174636000 ... A006939. Note that the columns sum to 1 1 2 3 5 7 11 15 22 ... cf. A000041
EXAMPLE
Starting a new row each time we are required to use a larger Ferrer board the triangle begins:
1
..1
.....2...1
.........2...3...3...1
.............2...2...6...7...6...4...1
.................2...2...4...8..12..15..17..14..10...5...1
.....................2...2...4
.........................2...2
.............................2
CROSSREFS
KEYWORD
more,nonn,tabf
AUTHOR
Alford Arnold, Jan 17 2008
STATUS
approved