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.

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A194547 Triangle read by rows: T(n,k) = Dyson's rank of the k-th partition of n, with partitions in lexicographic order.

Original entry on oeis.org

0, -1, 1, -2, 0, 2, -3, -1, 1, 0, 3, -4, -2, 0, -1, 2, 1, 4, -5, -3, -1, -2, 1, 0, 3, -1, 2, 1, 5, -6, -4, -2, -3, 0, -1, 2, -2, 1, 0, 4, 0, 3, 2, 6, -7, -5, -3, -4, -1, -2, 1, -3, 0, -1, 3, -1, 2, 1, 5, -2, 1, 0, 4, 3, 2, 7, -8, -6, -4, -5, -2, -3, 0, -4, -1
Offset: 1

Views

Author

Omar E. Pol, Dec 10 2011

Keywords

Comments

Row n has length A000041(n). The sum of row n is equal to zero.

Examples

			Written as a triangle:
  0;
  -1,1;
  -2,0,2;
  -3,-1,1,0,3;
  -4,-2,0,-1,2,1,4;
  -5,-3,-1,-2,1,0,3,-1,2,1,5;
  -6,-4,-2,-3,0,-1,2,-2,1,0,4,0,3,2,6;
  -7,-5,-3,-4,-1,-2,1,-3,0,-1,3,-1,2,1,5,-2,1,0,4,3,2,7;
		

Crossrefs

Programs

  • Maple
    T:= proc(n) local b, l;
          b:= proc(n, i, t)
                if n=0 then l:=l, i-t
              elif i>n then
              else b(n-i, i, t+1); b(n, i+1, t)
                fi
              end;
          l:= NULL; b(n, 1, 0); l
        end:
    seq(T(n), n=1..10);  # Alois P. Heinz, Dec 22 2011
  • Mathematica
    T[n_] := Module[{b, l}, b[n0_, i_, t_] := If [n0==0, l = Append[l, i-t], If[i>n0, , b[n0-i, i, t+1]; b[n0, i+1, t]]]; l = {}; b[n, 1, 0]; l];
    Table[T[n], {n, 1, 10}] // Flatten (* Jean-François Alcover, Mar 05 2021, after Alois P. Heinz *)

Formula

a(n) = A194546(n) - A193173(n).

Extensions

More terms from Alois P. Heinz, Dec 22 2011

A194548 Triangle read by rows: T(n,k) = number of parts in the k-th partition of n that does not contain 1 as a part, with partitions in lexicographic order.

Original entry on oeis.org

0, 1, 1, 2, 1, 2, 1, 3, 2, 2, 1, 3, 2, 2, 1, 4, 3, 3, 2, 2, 2, 1, 4, 3, 3, 2, 3, 2, 2, 1, 5, 4, 4, 3, 3, 3, 2, 3, 2, 2, 2, 1, 5, 4, 4, 3, 4, 3, 3, 2, 3, 3, 2, 2, 2, 1, 6, 5, 5, 4, 4, 4, 3, 4, 3, 3, 3, 2, 4, 3, 3, 2, 3, 2, 2, 2, 1, 6, 5, 5, 4, 5, 4, 4, 3, 4, 4, 3, 3, 3, 2, 4, 3, 3, 3, 2, 3, 2, 2, 2, 1
Offset: 1

Views

Author

Omar E. Pol, Dec 11 2011

Keywords

Examples

			Written as a triangle:
  0;
  1;
  1;
  2,1;
  2,1;
  3,2,2,1;
  3,2,2,1;
  4,3,3,2,2,2,1;
  4,3,3,2,3,2,2,1;
  5,4,4,3,3,3,2,3,2,2,2,1;
  5,4,4,3,4,3,3,2,3,3,2,2,2,1;
  6,5,5,4,4,4,3,4,3,3,3,2,4,3,3,2,3,2,2,2,1;
  6,5,5,4,5,4,4,3,4,4,3,3,3,2,4,3,3,3,2,3,2,2,2,1;
		

Crossrefs

Row sums give A138135. Row n has length A187219(n).

Programs

  • Maple
    T:= proc(n) local b, l;
          b:= proc(n, i, t)
                if n=0 then l:=l, t
              elif i>n then
              else b(n-i, i, t+1); b(n, i+1, t)
                fi
              end;
          if n<2 then 0 else l:= NULL; b(n, 2, 0); l fi
        end:
    seq(T(n), n=1..15);  # Alois P. Heinz, Dec 19 2011
  • Mathematica
    T[n_] := Module[{b, l}, b[n0_, i_, t_] :=
         If[n0==0, l = Append[l, t],
         If[i>n0, , b[n0-i, i, t+1]; b[n0, i+1, t]]];
         If[n<2, {0}, l = {}; b[n, 2, 0]; l]];
    Table[T[n], {n, 1, 15}]  // Flatten (* Jean-François Alcover, Mar 05 2021, after Alois P. Heinz *)

Extensions

More terms from Alois P. Heinz, Dec 19 2011

A194549 Triangle read by rows: T(n,k) = Dyson's rank of the k-th partition of n that does not contain 1 as a part, with partitions in lexicographic order.

Original entry on oeis.org

1, 1, 2, 0, 3, 1, 4, -1, 2, 1, 5, 0, 3, 2, 6, -2, 1, 0, 4, 3, 2, 7, -1, 2, 1, 5, 0, 4, 3, 8, -3, 0, -1, 3, 2, 1, 6, 1, 5, 4, 3, 9, -2, 1, 0, 4, -1, 3, 2, 7, 2, 1, 6, 5, 4, 10, -4, -1, -2, 2, 1, 0, 5, 0, 4, 3, 2, 8, -1, 3, 2, 7, 1, 6, 5, 4, 11, -3, 0, -1, 3, -2
Offset: 1

Views

Author

Omar E. Pol, Dec 11 2011

Keywords

Examples

			Written as a triangle:
  1;
  1;
  2;
  0,3;
  1,4;
  -1,2,1,5;
  0,3,2,6;
  -2,1,0,4,3,2,7;
  -1,2,1,5,0,4,3,8;
  -3,0,-1,3,2,1,6,1,5,4,3,9;
  -2,1,0,4,-1,3,2,7,2,1,6,5,4,10;
  -4,-1,-2,2,1,0,5,0,4,3,2,8,-1,3,2,7,1,6,5,4,11;
		

Crossrefs

The sum of row n is A000041(n-1). Row n has length A187219(n).

Programs

  • Maple
    T:= proc(n) local b, l;
          b:= proc(n, i, t)
                if n=0 then l:=l, i-t
              elif i>n then
              else b(n-i, i, t+1); b(n, i+1, t)
                fi
              end;
          if n<2 then 1 else l:= NULL; b(n, 2, 0); l fi
        end:
    seq(T(n), n=1..13); # Alois P. Heinz, Dec 20 2011
  • Mathematica
    T[n_] := Module[{b, l}, b[n0_, i_, t_] :=
         If[n0 == 0, l = Append[l, i-t],
         If[i>n0, , b[n0-i, i, t+1]; b[n0, i+1, t]]];
         If[n<2, {1}, l = {}; b[n, 2, 0]; l]];
    Table[T[n], {n, 1, 13}]  // Flatten (* Jean-François Alcover, Mar 05 2021, after Alois P. Heinz *)

Formula

a(n) = A141285(n) - A194548(n).

Extensions

More terms from Alois P. Heinz, Dec 20 2011

A194702 Triangle read by rows: T(k,m) = number of occurrences of k in the last section of the set of partitions of (2 + m).

Original entry on oeis.org

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

Views

Author

Omar E. Pol, Feb 05 2012

Keywords

Comments

Sub-triangle of A182703 and also of A194812. Note that the sum of every row is also the number of partitions of 2. For further information see A182703 and A135010.

Examples

			Triangle begins:
2,
0, 2,
1, 0, 1,
0, 1, 0, 1,
0, 0, 1, 0, 1,
0, 0, 0, 1, 0, 1,
0, 0, 0, 0, 1, 0, 1,
0, 0, 0, 0, 0, 1, 0, 1,
0, 0, 0, 0, 0, 0, 1, 0, 1,
0, 0, 0, 0, 0, 0, 0, 1, 0, 1,
...
For k = 1 and  m = 1; T(1,1) = 2 because there are two parts of size 1 in the last section of the set of partitions of 3, since 2 + m = 3, so a(1) = 2. For k = 2 and m = 1; T(2,1) = 0 because there are no parts of size 2 in the last section of the set of partitions of 3, since 2 + m = 3, so a(2) = 0.
		

Crossrefs

Always the sum of row k = p(2) = A000041(n) = 2.
The first (0-10) members of this family of triangles are A023531, A129186, this sequence, A194703-A194710.

Formula

T(k,m) = A182703(2+m,k), with T(k,m) = 0 if k > 2+m.
T(k,m) = A194812(2+m,k).

A194710 Triangle read by rows: T(k,m) = number of occurrences of k in the last section of the set of partitions of (10 + m).

Original entry on oeis.org

42, 15, 27, 10, 14, 18, 5, 10, 10, 17, 4, 5, 8, 10, 15, 2, 5, 4, 8, 9, 14, 2, 2, 4, 5, 7, 9, 13, 1, 2, 2, 4, 4, 8, 8, 13, 1, 1, 2, 2, 4, 4, 7, 9, 12, 0, 1, 1, 2, 2, 4, 4, 7, 8, 13, 1, 0, 1, 1, 2, 2, 4, 4, 7, 8, 12, 0, 1, 0, 1, 1, 2, 2, 4, 4, 7, 8, 12
Offset: 1

Views

Author

Omar E. Pol, Feb 05 2012

Keywords

Comments

Sub-triangle of A182703 and also of A194812. Note that the sum of row k is also the number of partitions of 10. For further information see A182703 and A135010.

Examples

			Triangle begins:
  42;
  15, 27;
  10, 14, 18;
   5, 10, 10, 17;
   4,  5,  8, 10, 15;
   2,  5,  4,  8,  9, 14;
   2,  2,  4,  5,  7,  9, 13;
   1,  2,  2,  4,  4,  8,  8, 13;
   1,  1,  2,  2,  4,  4,  7,  9, 12;
   0,  1,  1,  2,  2,  4,  4,  7,  8, 13;
   1,  0,  1,  1,  2,  2,  4,  4,  7,  8, 12;
   0,  1,  0,  1,  1,  2,  2,  4,  4,  7,  8, 12;
   0,  0,  1,  0,  1,  1,  2,  2,  4,  4,  7,  8, 12;
   0,  0,  0,  1,  0,  1,  1,  2,  2,  4,  4,  7,  8, 12;
  ...
For k = 1 and m = 1; T(1,1) = 42 because there are 42 parts of size 1 in the last section of the set of partitions of 11, since 10 + m = 11, so a(1) = 42. For k = 2 and m = 1; T(2,1) = 15 because there are 15 parts of size 2 in the last section of the set of partitions of 11, since 10 + m = 11, so a(2) = 15.
		

Crossrefs

Always the sum of row k = p(10) = A000041(10) = 42.
The first (0-10) members of this family of triangles are A023531, A129186, A194702-A194709, this sequence.

Formula

T(k,m) = A182703(10+m,k), with T(k,m) = 0 if k > 10+m.
T(k,m) = A194812(10+m,k).
Beginning with row k=11 each row starts with (k-11) 0's and ends with the subsequence 1, 0, 1, 1, 2, 2, 4, 4, 7, 8, 12, the initial terms of A002865. - Alois P. Heinz, Feb 15 2012

A196931 Triangle read by rows in which row n lists in nondecreasing order the smallest part of every partition of n.

Original entry on oeis.org

0, 1, 1, 2, 1, 1, 3, 1, 1, 1, 2, 4, 1, 1, 1, 1, 1, 2, 5, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 6, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 7, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 4, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 0

Views

Author

Omar E. Pol, Oct 21 2011

Keywords

Comments

If n >= 1, row n lists the smallest parts of every partition of n in the order produced by the shell model of partitions of A135010, hence row n lists the parts of the last section of the set of partitions of n, except the emergent parts (See A182699).
Row n has length A000041(n). Row sums give A046746. Right border of triangle gives A001477. Row n starts with A000041(n-1) ones, n >= 1.

Examples

			Written as a triangle:
  0,
  1,
  1,2,
  1,1,3,
  1,1,1,2,4,
  1,1,1,1,1,2,5,
  1,1,1,1,1,1,1,2,2,3,6
  1,1,1,1,1,1,1,1,1,1,1,2,2,3,7,
  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,3,4,8,
  ...
		

Crossrefs

A211999 A list of ordered partitions of the positive integers in which the shells of each integer are assembled by their tails.

Original entry on oeis.org

1, 1, 1, 2, 2, 1, 1, 1, 1, 3, 3, 1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 4, 4, 1, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 2, 5, 5, 1, 3, 2, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 4, 1, 1, 2, 2, 2, 4, 2, 3, 3, 6, 6, 1, 3, 3, 1, 4, 2, 1, 2, 2, 2, 1, 4, 1, 1, 1, 2, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 3, 2, 1, 1, 5, 1, 1, 3, 2, 2, 5, 2, 4, 3, 7
Offset: 1

Views

Author

Omar E. Pol, Aug 14 2012

Keywords

Comments

The sequence lists the partitions of all positive integers. Each row of the irregular array is a partition of j.
At stage 1, we start with 1.
At stage j > 1, we write the partitions of j using the following rules:
First we copy the last A000041(j-1) rows of the array in descending order, as a mirror image, starting with the row that contains the part of size j-1. At the end of each new row, we added a part of size 1.
Second, we write the partitions of j that do not contain 1 as a part, in reverse-lexicographic order, such that the last row (or partition of j) is j.
Note that the table can be partially folded. In this case we have a three-dimensional structure in which each column contains parts of the same size (see example). Also the table can be completely folded, therefore stacked parts have the same size.

Examples

			A table of partitions.
---------------------------------------------------------
.              Expanded       Geometric  Side view of the
Partitions     version        model      folded table
---------------------------------------------------------
1;             1;             |*|                /
---------------------------------------------------------
1,1;           1,1;           |o|*|              \
2;             . 2;           |* *|               \
---------------------------------------------------------
2,1;           . 2,1;         |o o|*|             /
1,1,1;         1,1,1;         |o|o|*|            /
3;             . . 3;         |* * *|           /
---------------------------------------------------------
3,1;           . . 3,1;       |o o o|*|         \
1,1,1,1;       1,1,1,1;       |o|o|o|*|          \
2,1,1;         . 2,1,1;       |o o|o|*|           \
2,2;           . 2,. 2;       |* *|* *|            \
4;             . . . 4;       |* * * *|             \
---------------------------------------------------------
4,1;           . . . 4,1;     |o o o o|*|           /
2,2,1;         . 2,. 2,1;     |o o|o o|*|          /
2,1,1,1;       . 2,1,1,1;     |o o|o|o|*|         /
1,1,1,1,1;     1,1,1,1,1;     |o|o|o|o|*|        /
3,1,1;         . . 3,1,1;     |o o o|o|*|       /
3,2;           . . 3,. 2;     |* * *|* *|      /
5;             . . . . 5;     |* * * * *|     /
---------------------------------------------------------
5,1;           . . . . 5,1;   |o o o o o|*|   \
3,2,1;         . . 3,. 2,1;   |o o o|o o|*|    \
3,1,1,1;       . . 3,1,1,1;   |o o o|o|o|*|     \
1,1,1,1,1,1;   1,1,1,1,1,1;   |o|o|o|o|o|*|      \
2,1,1,1,1;     . 2,1,1,1,1;   |o o|o|o|o|*|       \
2,2,1,1;       . 2,. 2,1,1;   |o o|o o|o|*|        \
4,1,1;         . . . 4,1,1;   |o o o o|o|*|         \
2,2,2;         . 2, .2,. 2;   |* *|* *|* *|          \
4,2;           . . . 4,. 2;   |* * * *|* *|           \
3,3;           . . 3,. . 3;   |* * *|* * *|            \
6;             . . . . . 6;   |* * * * * *|             \
---------------------------------------------------------
Note that * is a unitary element of every part of the last section of j.
		

Crossrefs

Rows sums give A036042, n>=1.
Other versions are A211983, A211984, A211989. See also A026792, A211992-A211994. Spiral arrangements are A211985-A211988, A211995-A211998.

A168016 Triangle T(n,k) read by rows in which row n list the number of partitions of n into parts divisible by k for k=n,n-1,...,1.

Original entry on oeis.org

1, 1, 2, 1, 0, 3, 1, 0, 2, 5, 1, 0, 0, 0, 7, 1, 0, 0, 2, 3, 11, 1, 0, 0, 0, 0, 0, 15, 1, 0, 0, 0, 2, 0, 5, 22, 1, 0, 0, 0, 0, 0, 3, 0, 30, 1, 0, 0, 0, 0, 2, 0, 0, 7, 42, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 56, 1, 0, 0, 0, 0, 0, 2, 0, 3, 5, 11, 77, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 101
Offset: 1

Views

Author

Omar E. Pol, Nov 21 2009

Keywords

Examples

			Triangle begins:
==============================================
.... k: 12 11 10. 9. 8. 7. 6. 5. 4. 3.. 2.. 1.
==============================================
n=1 ....................................... 1,
n=2 ................................... 1,  2,
n=3 ............................... 1,  0,  3,
n=4 ............................ 1, 0,  2,  5,
n=5 ......................... 1, 0, 0,  0,  7,
n=6 ...................... 1, 0, 0, 2,  3, 11,
n=7 ................... 1, 0, 0, 0, 0,  0, 15,
n=8 ................ 1, 0, 0, 0, 2, 0,  5, 22,
n=9 ............. 1, 0, 0, 0, 0, 0, 3,  0, 30,
n=10 ......... 1, 0, 0, 0, 0, 2, 0, 0,  7, 42,
n=11 ...... 1, 0, 0, 0, 0, 0, 0, 0, 0,  0, 56,
n=12 ... 1, 0, 0, 0, 0, 0, 2, 0, 3, 5, 11, 77,
...
		

Crossrefs

Programs

  • Mathematica
    T[n_, k_]:= If[IntegerQ[n/(n-k+1)], PartitionsP[n/(n-k+1)], 0];
    Table[T[n, k], {n,15}, {k,n}]//Flatten (* G. C. Greubel, Jan 12 2023 *)
  • SageMath
    def T(n,k): return number_of_partitions(n/(n-k+1)) if (n%(n-k+1))==0 else 0
    flatten([[T(n,k) for k in range(1,n+1)] for n in range(1,16)]) # G. C. Greubel, Jan 12 2023

Formula

T(n, k) = A000041(n/k) if k|n; otherwise T(n,k) = 0.
T(n, n) = A000041(n).
From G. C. Greubel, Jan 12 2023: (Start)
T(2*n, n) = A000007(n-1).
Sum_{k=1..n} T(n, k) = A047968(n).
Sum_{k=2..n-1} T(n, k) = A168111(n-1). (End)

Extensions

Edited and extended by Max Alekseyev, May 07 2010

A168017 Triangle read by rows in which row n lists the number of partitions of n into parts divisible by d, where d is a divisor of n listed in decreasing order.

Original entry on oeis.org

1, 1, 2, 1, 3, 1, 2, 5, 1, 7, 1, 2, 3, 11, 1, 15, 1, 2, 5, 22, 1, 3, 30, 1, 2, 7, 42, 1, 56, 1, 2, 3, 5, 11, 77, 1, 101, 1, 2, 15, 135, 1, 3, 7, 176, 1, 2, 5, 22, 231, 1, 297, 1, 2, 3, 11, 30, 385, 1, 490, 1, 2, 5, 7, 42, 627, 1, 3, 15, 792, 1, 2, 56, 1002
Offset: 1

Views

Author

Omar E. Pol, Nov 22 2009

Keywords

Comments

Positive values of triangle A168016.
The number of terms of row n is equal to the number of divisors of n: A000005(n).
Note that the last term of each row is the number of partitions of n: A000041(n).
Also, it appears that row n lists the partition numbers of the divisors of n. [Omar E. Pol, Nov 23 2009]

Examples

			Consider row n=8: (1, 2, 5, 22). The divisors of 8 listed in decreasing order are 8, 4, 2, 1 (see A056538). There is 1 partition of 8 into parts divisible by 8. Also, there are 2 partitions of 8 into parts divisible by 4: {(8), (4+4)}; 5 partitions of 8 into parts divisible by 2: {(8), (6+2), (4+4), (4+2+2), (2+2+2+2)}; and 22 partitions of 8 into parts divisible by 1, because A000041(8)=22. Then row 8 is formed by 1, 2, 5, 22.
Triangle begins:
1;
1,  2;
1,  3;
1,  2,  5;
1,  7;
1,  2,  3, 11;
1, 15;
1,  2,  5, 22;
1,  3, 30;
1,  2,  7, 42;
1, 56;
1,  2,  3,  5, 11, 77;
		

Crossrefs

Programs

  • Maple
    with(numtheory):
    b:= proc(n, i, d) option remember;
          if n<0 then 0
        elif n=0 then 1
        elif i<1 then 0
        else b(n, i-d, d) +b(n-i, i, d)
          fi
        end:
    T:= proc(n) local l;
          l:= sort([divisors(n)[]],`>`);
          seq(b(n, n, l[i]), i=1..nops(l))
        end:
    seq(T(n), n=1..30); # Alois P. Heinz, Oct 21 2011
  • Mathematica
    b[n_, i_, d_] := b[n, i, d] = Which[n<0, 0, n==0, 1, i<1, 0, True, b[n, i - d, d] + b[n-i, i, d]]; T[n_] := Module[{l = Divisors[n] // Reverse}, Table[b[n, n, l[[i]]], {i, 1, Length[l]}]]; Table[T[n], {n, 1, 30}] // Flatten (* Jean-François Alcover, Dec 03 2015, after Alois P. Heinz *)

A182700 Triangle T(n,k) = n*A000041(n-k), 0<=k<=n, read by rows.

Original entry on oeis.org

0, 1, 1, 4, 2, 2, 9, 6, 3, 3, 20, 12, 8, 4, 4, 35, 25, 15, 10, 5, 5, 66, 42, 30, 18, 12, 6, 6, 105, 77, 49, 35, 21, 14, 7, 7, 176, 120, 88, 56, 40, 24, 16, 8, 8, 270, 198, 135, 99, 63, 45, 27, 18, 9, 9, 420, 300, 220, 150, 110, 70, 50, 30, 20, 10, 10, 616, 462, 330, 242, 165, 121, 77, 55, 33
Offset: 0

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Author

Omar E. Pol, Nov 27 2010

Keywords

Comments

T(n,k) is the sum of the parts of all partitions of n that contain k as a part, assuming that all partitions of n have 0 as a part: Thus, column 0 gives the sum of the parts of all partitions of n.
By definition all entries in row n>0 are divisible by n.
Row sums are 0, 2, 8, 21, 48, 95, 180, 315, 536, 873, 1390, 2145,...
The partitions of n+k that contain k as a part can be obtained by adding k to every partition of n assuming that all partitions of n have 0 as a part.
For example, the partitions of 6+k that contain k as a part are
k + 6
k + 3 + 3
k + 4 + 2
k + 2 + 2 + 2
k + 5 + 1
k + 3 + 2 + 1
k + 4 + 1 + 1
k + 2 + 2 + 1 + 1
k + 3 + 1 + 1 + 1
k + 2 + 1 + 1 + 1 + 1
k + 1 + 1 + 1 + 1 + 1 + 1
The partition number A000041(n) is also the number of partitions of m*(n+k) into parts divisible by m and that contain m*k as a part, with k>=0, m>=1, n>=0 and assuming that all partitions of n have 0 as a part.

Examples

			For n=7 and k=4 there are 3 partitions of 7 that contain 4 as a part. These partitions are (4+3)=7, (4+2+1)=7 and (4+1+1+1)=7. The sum is 7+7+7 = 7*3 = 21. By other way, the partition number of 7-4 is A000041(3) = p(3)=3, then 7*3 = 21, so T(7,4) = 21.
Triangle begins with row n=0 and columns 0<=k<=n :
0,
1, 1,
4, 2, 2,
9, 6, 3, 3,
20,12,8, 4, 4,
35,25,15,10,5, 5,
66,42,30,18,12,6, 6
		

Crossrefs

Two triangles that are essentially the same as this are A027293 and A140207. - N. J. A. Sloane, Nov 28 2010
Row sums give A182704.

Programs

  • Maple
    A182700 := proc(n,k) n*combinat[numbpart](n-k) ; end proc:
    seq(seq(A182700(n,k),k=0..n),n=0..15) ;
  • Mathematica
    Table[n*PartitionsP[n-k], {n, 0, 11}, {k, 0, n}] // Flatten (* Robert Price, Jun 23 2020 *)
  • PARI
    A182700(n,k) = n*numbpart(n-k)

Formula

T(n,0) = A066186(n).
T(n,k) = A182701(n,k), n>=1 and k>=1.
T(n,n) = n = min { T(n,k); 0<=k<=n }.
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