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A296772
Triangle read by rows in which row n lists the compositions of n ordered first by decreasing length and then reverse-lexicographically.
9
1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 3, 1, 2, 2, 1, 3, 4, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 3, 1, 1, 2, 2, 1, 2, 1, 2, 1, 3, 1, 1, 2, 2, 1, 1, 3, 4, 1, 3, 2, 2, 3, 1, 4, 5, 1, 1, 1, 1, 1, 1, 2
OFFSET
1,4
COMMENTS
The ordering of compositions in each row is consistent with the reverse-Mathematica ordering of expressions (cf. A124734).
Length of k-th composition is A124748(k-1)+1. - Andrey Zabolotskiy, Dec 20 2017
EXAMPLE
Triangle of compositions begins:
(1),
(11),(2),
(111),(21),(12),(3),
(1111),(211),(121),(112),(31),(22),(13),(4),
(11111),(2111),(1211),(1121),(1112),(311),(221),(212),(131),(122),(113),(41),(32),(23),(14),(5).
MATHEMATICA
Table[Reverse[Sort[Join@@Permutations/@IntegerPartitions[n]]], {n, 6}]
KEYWORD
nonn,tabf
AUTHOR
Gus Wiseman, Dec 20 2017
STATUS
approved