OFFSET
1,2
COMMENTS
First differs from A334439 for partitions of 9. Namely, this sequence has (4,4,1) before (5,2,2), while A334439 has (5,2,2) before (4,4,1). - Gus Wiseman, May 08 2020
This is also a list of all the possible prime signatures of a number, arranged in graded colexicographic ordering. - N. J. A. Sloane, Feb 09 2014
This is also the Abramowitz-Stegun ordering of reversed partitions (A036036) if the partitions are reversed again after sorting. Partitions sorted first by sum and then colexicographically are A211992. - Gus Wiseman, May 08 2020
LINKS
Robert Price, Table of n, a(n) for n = 1..3615, 15 rows.
Wikiversity, Lexicographic and colexicographic order
EXAMPLE
First five rows are:
{{1}}
{{2}, {1, 1}}
{{3}, {2, 1}, {1, 1, 1}}
{{4}, {3, 1}, {2, 2}, {2, 1, 1}, {1, 1, 1, 1}}
{{5}, {4, 1}, {3, 2}, {3, 1, 1}, {2, 2, 1}, {2, 1, 1, 1}, {1, 1, 1, 1, 1}}
Up to the fifth row, this is exactly the same as the reverse lexicographic ordering A080577. The first row which differs is the sixth one, which reads ((6), (5,1), (4,2), (3,3), (4,1,1), (3,2,1), (2,2,2), (3,1,1,1), (2,2,1,1), (2,1,1,1,1), (1,1,1,1,1,1)). - M. F. Hasler, Jan 23 2020
From Gus Wiseman, May 08 2020: (Start)
The sequence of all partitions begins:
() (3,2) (2,1,1,1,1)
(1) (3,1,1) (1,1,1,1,1,1)
(2) (2,2,1) (7)
(1,1) (2,1,1,1) (6,1)
(3) (1,1,1,1,1) (5,2)
(2,1) (6) (4,3)
(1,1,1) (5,1) (5,1,1)
(4) (4,2) (4,2,1)
(3,1) (3,3) (3,3,1)
(2,2) (4,1,1) (3,2,2)
(2,1,1) (3,2,1) (4,1,1,1)
(1,1,1,1) (2,2,2) (3,2,1,1)
(5) (3,1,1,1) (2,2,2,1)
(4,1) (2,2,1,1) (3,1,1,1,1)
(End)
MATHEMATICA
Reverse/@Join@@Table[Sort[Reverse/@IntegerPartitions[n]], {n, 8}] (* Gus Wiseman, May 08 2020 *)
- or -
colen[f_, c_]:=OrderedQ[{Reverse[f], Reverse[c]}];
Join@@Table[Sort[IntegerPartitions[n], colen], {n, 8}] (* Gus Wiseman, May 08 2020 *)
CROSSREFS
See A036036 for the graded reflected colexicographic ("Abramowitz and Stegun" or Hindenburg) ordering.
See A080576 for the graded reflected lexicographic ("Maple") ordering.
See A080577 for the graded reverse lexicographic ("Mathematica") ordering: differs from a(48) on!
See A228100 for the Fenner-Loizou (binary tree) ordering.
Partition lengths are A036043.
Reversing all partitions gives A036036.
The number of distinct parts is A103921.
Taking Heinz numbers gives A185974.
The version ignoring length is A211992.
The version for revlex instead of colex is A334439.
Lexicographically ordered reversed partitions are A026791.
Reverse-lexicographically ordered partitions are A080577.
Sorting partitions by Heinz number gives A296150.
KEYWORD
nonn,easy,tabf
AUTHOR
EXTENSIONS
Name corrected by Gus Wiseman, May 12 2020
Mathematica programs corrected to reflect offset of one and not zero by Robert Price, Jun 04 2020
STATUS
approved