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.

Showing 1-3 of 3 results.

A373241 T(n,k) is the difference between the number of different parts and the number of different multiplicities in the k-th partition of n in graded reverse lexicographic ordering (A080577).

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 2, 0, 0, 1, 0, 0, 0, 1, 1, 0, 1, 2, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 2, 0, 0, 2, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 2, 0, 1, 2, 0, 1, 0, 0, 2, 1, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 1, 2, 0, 1, 2, 0, 1, 0, 0, 2, 2, 1, 1, 1, 0, 0, 1, 0, 3, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0
Offset: 1

Views

Author

Olivier Gérard, May 29 2024

Keywords

Comments

This difference is always nonnegative.
The number of zero values in each row is A098859.
The number of ones in each row is A325244.
The number of positive entries in each row is A336866.
The corresponding regular triangle for partitions of n of length k is A373242.
The sum of each row is A373243.

Examples

			The array begins
  0
  0,0
  0,1,0
  0,1,0,0,0
  0,1,1,0,0,0,0
  0,1,1,0,0,2,0,0,1,0,0
  0,1,1,0,1,2,0,0,0,1,0,0,0,0,0
  0,1,1,0,1,2,0,0,2,0,1,0,0,1,1,1,0,0,0,0,0,0
  0,1,1,0,1,2,0,1,2,0,1,0,0,2,1,1,1,0,0,1,0,0,1,1,0,0,1,0,0,0
  ...
		

Crossrefs

Cf. A373269 a triangle of the same shape and order for number of multiplicities.

Programs

  • Mathematica
    Flatten @ Table[
      Map[Length[Union[#]] - Length[Union[Length /@ Split[#]]] &,
       IntegerPartitions[n]], {n, 1, 20}]

A373271 a(n) = sum for all integer partitions of n of the number of distinct multiplicities in each partition.

Original entry on oeis.org

1, 2, 3, 6, 10, 14, 24, 34, 49, 70, 103, 134, 195, 258, 347, 461, 624, 796, 1066, 1358, 1763, 2250, 2903, 3631, 4644, 5805, 7309, 9083, 11381, 13998, 17428, 21369, 26336, 32174, 39451, 47847, 58399, 70610, 85590, 103077, 124462, 149169, 179368, 214300, 256397
Offset: 1

Views

Author

Olivier Gérard, May 29 2024

Keywords

Comments

Sum of the rows of A373269.
Sum of the rows of A373270.
The multiplicity of a part in an integer partition (or composition) is the number of times it appears in the partition, seen as a list.
The multiplicity of 3 in the partition 12 = 5+3+3+1 is 2.
For this sequence, only distinct multiplicities appearing for parts of the partition are counted, only once for a given partition.
If all multiplicities of all parts of all integer partitions of n are counted, one gets A000070 (1, 2, 4, 7, 12, 19, 30, 45, 67, 97, ...).
If all distinct multiplicities of all parts of all integer partitions are summed, one gets A373273 (1, 3, 5, 11, 18, 29, 48, 74, 107, 161, ...).
If all multiplicities of all parts of all integer partitions of n are summed, one gets A006128 (1, 3, 6, 12, 20, 35, 54, 86, 128, 192, ...).

Examples

			Example for n=20:
the partition 20=4+3+3+3+3+2+1+1
has multiplicities 1, 4, 1, 2
for the parts 4,3,2,1 listed in descending order.
It has 3 different multiplicities (1, 2 and 4) and contributes 3 to a(20) = 1358.
		

Crossrefs

Programs

  • Mathematica
    Table[Plus @@
      Table[Plus @@
        Map[Length[Union[Length /@ Split[#]]] &,
         IntegerPartitions[n, {k}]], {k, 1, n}], {n, 1, 40}]

A373270 Triangle read by rows: T(n,k) is the sum for all integer partitions of n of length k of the number of different multiplicities.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 4, 2, 1, 1, 3, 4, 3, 2, 1, 1, 3, 7, 6, 4, 2, 1, 1, 4, 8, 8, 6, 4, 2, 1, 1, 4, 10, 12, 10, 5, 4, 2, 1, 1, 5, 12, 15, 13, 11, 6, 4, 2, 1, 1, 5, 15, 21, 20, 17, 11, 6, 4, 2, 1, 1, 6, 16, 25, 26, 21, 16, 10, 6, 4, 2, 1, 1, 6, 20, 33, 36, 34, 24, 17, 11, 6, 4, 2, 1, 1, 7, 22, 38, 46, 44, 34, 25, 17, 11, 6, 4, 2, 1, 1, 7, 25, 48, 58, 56, 50, 38, 24, 16, 11, 6, 4, 2, 1
Offset: 1

Views

Author

Olivier Gérard, May 29 2024

Keywords

Examples

			Array begins:
  1,
  1, 1,
  1, 1,  1,
  1, 2,  2,  1,
  1, 2,  4,  2,  1,
  1, 3,  4,  3,  2,  1,
  1, 3,  7,  6,  4,  2,  1,
  1, 4,  8,  8,  6,  4,  2, 1,
  1, 4, 10, 12, 10,  5,  4, 2, 1,
  1, 5, 12, 15, 13, 11,  6, 4, 2, 1,
  1, 5, 15, 21, 20, 17, 11, 6, 4, 2, 1,
  ...
Example of computation:
T(9,3) = 10 because the partitions of 9 into 3 parts are
  7+1+1, 6+2+1, 5+3+1, 5+2+2, 4+4+1, 4+3+2, 3+3+3,
the number of different multiplicities are
  2, 1, 1, 2, 2, 1, 1,
and the sum of these multiplicities is 10.
		

Crossrefs

Programs

  • Mathematica
    Flatten@Table[
      Plus @@@
       Table[Map[Length[Union[Length /@ Split[#]]] &,
         IntegerPartitions[n, {k}]], {k, 1, n}], {n, 1, 20}]
Showing 1-3 of 3 results.