cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A118457 Table of partitions of n into distinct parts, in Mathematica ordering.

Original entry on oeis.org

1, 2, 3, 2, 1, 4, 3, 1, 5, 4, 1, 3, 2, 6, 5, 1, 4, 2, 3, 2, 1, 7, 6, 1, 5, 2, 4, 3, 4, 2, 1, 8, 7, 1, 6, 2, 5, 3, 5, 2, 1, 4, 3, 1, 9, 8, 1, 7, 2, 6, 3, 6, 2, 1, 5, 4, 5, 3, 1, 4, 3, 2, 10, 9, 1, 8, 2, 7, 3, 7, 2, 1, 6, 4, 6, 3, 1, 5, 4, 1, 5, 3, 2, 4, 3, 2, 1, 11, 10, 1, 9, 2, 8, 3, 8, 2, 1, 7, 4, 7, 3, 1, 6, 5
Offset: 1

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Comments

Reverse lexicographic order where the partitions are reprepresented as (weakly) decreasing lists of parts. [Joerg Arndt, Jan 25 2013]

Examples

			The partitions of 5 into distinct parts are [5], [4,1] and [3,2], so row 5 is 5,4,1,3,2.
1;
2;
3; 2,1;
4; 3,1;
5; 4,1; 3,2;
6; 5,1; 4,2; 3,2,1;
7; 6,1; 5,2; 4,3; 4,2,1;
8; 7,1; 6,2; 5,3; 5,2,1; 4,3,1;
9; 8,1; 7,2; 6,3; 6,2,1; 5,4; 5,3,1; 4,3,2;
10; 9,1; 8,2; 7,3; 7,2,1; 6,4; 6,3,1; 5,4,1; 5,3,2; 4,3,2,1;
11; 10,1; 9,2; 8,3; 8,2,1; 7,4; 7,3,1; 6,5; 6,4,1; 6,3,2; 5,4,2; 5,3,2,1;
		

Crossrefs

Cf. A026793, A118459 (partition lengths), A015723 (total row lengths), A080577, A000009, A246688.

Programs

  • Mathematica
    d[n_] := Select[IntegerPartitions[n], Max[Length /@ Split@ #] == 1 &]; Flatten[Table[d[n], {n, 15}]] (* Clark Kimberling, Mar 11 2012 *)
  • SageMath
    def StrictPartitions(n): return [partition for partition in Partitions(n) if Set(partition.to_exp()).issubset(Set([0,1]))]
    def A118457row(n): return [p for parts in StrictPartitions(n) for p in parts]
    for n in (1..9): print(A118457row(n)) # Peter Luschny, Apr 11 2020