OFFSET
1,2
COMMENTS
Mirror of triangle A135010.
LINKS
Robert Price, Table of n, a(n) for n = 1..16851, 25 rows
Omar E. Pol, A section model of partitions (2D and 3D) [From Omar E. Pol, Sep 07 2008]
Robert Price, Mathematica Program to Generate Diagram
EXAMPLE
Triangle begins:
[1];
[2],[1];
[3],[1],[1];
[4],[2,2],[1],[1],[1];
[5],[3,2],[1],[1],[1],[1],[1];
[6],[3,3],[4,2],[2,2,2],[1],[1],[1],[1],[1],[1],[1];
[7],[4,3],[5,2],[3,2,2],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1],[1];
...
The illustration of the three views of the section model of partitions (version "tree" with seven sections) shows the connection between several sequences.
---------------------------------------------------------
Partitions A194805 Table 1.0
---------------------------------------------------------
7 15 7 7 . . . . . .
4+3 4 4 . . . 3 . .
5+2 5 5 . . . . 2 .
3+2+2 3 3 . . 2 . 2 .
6+1 11 6 1 6 . . . . . 1
3+3+1 3 1 3 . . 3 . . 1
4+2+1 4 1 4 . . . 2 . 1
2+2+2+1 2 1 2 . 2 . 2 . 1
5+1+1 7 1 5 5 . . . . 1 1
3+2+1+1 1 3 3 . . 2 . 1 1
4+1+1+1 5 4 1 4 . . . 1 1 1
2+2+1+1+1 2 1 2 . 2 . 1 1 1
3+1+1+1+1 3 1 3 3 . . 1 1 1 1
2+1+1+1+1+1 2 2 1 2 . 1 1 1 1 1
1+1+1+1+1+1+1 1 1 1 1 1 1 1 1 1
. 1 ---------------
. *<------- A000041 -------> 1 1 2 3 5 7 11
. A182712 -------> 1 0 2 1 4 3
. A182713 -------> 1 0 1 2 2
. A182714 -------> 1 0 1 1
. 1 0 1
---------------------------------------------------------
. A138137 --> 1 2 3 6 9 15..
---------------------------------------------------------
---------------------------------------------------------
.
. . . . . 1 . . . .
. . . . 2 1 . . . .
. . 3 . . 1 2 . . .
. Table 2.0 . . 2 2 1 . . 3 . Table 2.1
. . . . . 1 2 2 . .
. 1 . . . .
.
---------------------------------------------------------
.
From Omar E. Pol, Sep 03 2013: (Start)
Illustration of initial terms (n = 1..6). The table shows the six sections of the set of partitions of 6. Note that before the dissection the set of partitions was in the ordering mentioned in A026792. More generally, the six sections of the set of partitions of 6 also can be interpreted as the first six sections of the set of partitions of any integer >= 6.
Illustration of initial terms:
---------------------------------------
n j Diagram Parts
---------------------------------------
. _
1 1 |_| 1;
. _ _
2 1 |_ | 2,
2 2 |_| . 1;
. _ _ _
3 1 |_ _ | 3,
3 2 | | . 1,
3 3 |_| . . 1;
. _ _ _ _
4 1 |_ _ | 4,
4 2 |_ _|_ | 2, 2,
4 3 | | . 1,
4 4 | | . . 1,
4 5 |_| . . . 1;
. _ _ _ _ _
5 1 |_ _ _ | 5,
5 2 |_ _ _|_ | 3, 2,
5 3 | | . 1,
5 4 | | . . 1,
5 5 | | . . 1,
5 6 | | . . . 1,
5 7 |_| . . . . 1;
. _ _ _ _ _ _
6 1 |_ _ _ | 6,
6 2 |_ _ _|_ | 3, 3,
6 3 |_ _ | | 4, 2,
6 4 |_ _|_ _|_ | 2, 2, 2,
6 5 | | . 1,
6 6 | | . . 1,
6 7 | | . . 1,
6 8 | | . . . 1,
6 9 | | . . . 1,
6 10 | | . . . . 1,
6 11 |_| . . . . . 1;
...
(End)
MATHEMATICA
less[run1_, run2_] := (lg1 = run1 // Length; lg2 = run2 // Length; lg = Max[lg1, lg2]; r1 = If[lg1 == lg, run1, PadRight[run1, lg, 0]]; r2 = If[lg2 == lg, run2, PadRight[run2, lg, 0]]; Order[r1, r2] != -1); row[n_] := Join[Array[1 &, {PartitionsP[n - 1]}], Sort[Reverse /@ Select[IntegerPartitions[n], FreeQ[#, 1] &], less]] // Flatten // Reverse; Table[row[n], {n, 1, 9}] // Flatten (* Jean-François Alcover, Jan 15 2013 *)
Table[Reverse/@Reverse@DeleteCases[Sort@PadRight[Reverse/@Cases[IntegerPartitions[n], x_ /; Last[x]!=1]], x_ /; x==0, 2]~Join~ConstantArray[{1}, PartitionsP[n - 1]], {n, 1, 9}] // Flatten (* Robert Price, May 11 2020 *)
CROSSREFS
KEYWORD
nonn,tabf,less
AUTHOR
Omar E. Pol, Mar 21 2008
STATUS
approved