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 1-6 of 6 results.

A365924 Number of incomplete integer partitions of n, meaning not every number from 0 to n is the sum of some submultiset.

Original entry on oeis.org

0, 0, 1, 1, 3, 3, 6, 7, 12, 14, 22, 25, 38, 46, 64, 76, 106, 124, 167, 199, 261, 309, 402, 471, 604, 714, 898, 1053, 1323, 1542, 1911, 2237, 2745, 3201, 3913, 4536, 5506, 6402, 7706, 8918, 10719, 12364, 14760, 17045, 20234, 23296, 27600, 31678, 37365, 42910, 50371, 57695, 67628, 77300, 90242, 103131, 119997
Offset: 0

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Author

Gus Wiseman, Sep 26 2023

Keywords

Comments

The complement (complete partitions) is A126796.

Examples

			The a(0) = 0 through a(8) = 12 partitions:
  .  .  (2)  (3)  (4)    (5)    (6)      (7)      (8)
                  (2,2)  (3,2)  (3,3)    (4,3)    (4,4)
                  (3,1)  (4,1)  (4,2)    (5,2)    (5,3)
                                (5,1)    (6,1)    (6,2)
                                (2,2,2)  (3,2,2)  (7,1)
                                (4,1,1)  (3,3,1)  (3,3,2)
                                         (5,1,1)  (4,2,2)
                                                  (4,3,1)
                                                  (5,2,1)
                                                  (6,1,1)
                                                  (2,2,2,2)
                                                  (5,1,1,1)
		

Crossrefs

For parts instead of sums we have A047967/A365919, ranks A080259/A055932.
The complement is A126796, ranks A325781, strict A188431.
These partitions have ranks A365830.
The strict case is A365831.
Row sums of A365923 without the first column, strict A365545.
A000041 counts integer partitions, strict A000009.
A046663 counts partitions w/o a submultiset summing to k, strict A365663.
A276024 counts positive subset-sums of partitions, strict A284640.
A325799 counts non-subset-sums of prime indices.
A364350 counts combination-free strict partitions.
A365543 counts partitions with a submultiset summing to k, strict A365661.

Programs

  • Mathematica
    nmz[y_]:=Complement[Range[Total[y]],Total/@Subsets[y]];
    Table[Length[Select[IntegerPartitions[n],Length[nmz[#]]>0&]],{n,0,15}]

Formula

a(n) = A000041(n) - A126796(n).

A365830 Heinz numbers of incomplete integer partitions, meaning not every number from 0 to A056239(n) is the sum of some submultiset.

Original entry on oeis.org

3, 5, 7, 9, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 25, 26, 27, 28, 29, 31, 33, 34, 35, 37, 38, 39, 41, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 57, 58, 59, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 81, 82, 83, 85, 86, 87, 88, 89
Offset: 1

Views

Author

Gus Wiseman, Sep 26 2023

Keywords

Comments

First differs from A325798 in lacking 156.
The Heinz number of a partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k). This gives a bijective correspondence between positive integers and integer partitions.
The complement (complete partitions) is A325781.

Examples

			The terms together with their prime indices begin:
   3: {2}
   5: {3}
   7: {4}
   9: {2,2}
  10: {1,3}
  11: {5}
  13: {6}
  14: {1,4}
  15: {2,3}
  17: {7}
  19: {8}
  21: {2,4}
  22: {1,5}
  23: {9}
  25: {3,3}
  26: {1,6}
  27: {2,2,2}
  28: {1,1,4}
For example, the submultisets of (1,1,2,6) (right column) and their sums (left column) are:
   0: ()
   1: (1)
   2: (2)  or (11)
   3: (12)
   4: (112)
   6: (6)
   7: (16)
   8: (26) or (116)
   9: (126)
  10: (1126)
But 5 is missing, so 156 is in the sequence.
		

Crossrefs

For prime indices instead of sums we have A080259, complement of A055932.
The complement is A325781, counted by A126796, strict A188431.
Positions of nonzero terms in A325799, complement A304793.
These partitions are counted by A365924, strict A365831.
A056239 adds up prime indices, row sums of A112798.
A276024 counts positive subset-sums of partitions, strict A284640
A299701 counts distinct subset-sums of prime indices.
A365918 counts distinct non-subset-sums of partitions, strict A365922.
A365923 counts partitions by distinct non-subset-sums, strict A365545.

Programs

  • Mathematica
    prix[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
    nmz[y_]:=Complement[Range[Total[y]],Total/@Subsets[y]];
    Select[Range[100],Length[nmz[prix[#]]]>0&]

A365918 Number of distinct non-subset-sums of integer partitions of n.

Original entry on oeis.org

0, 1, 2, 6, 8, 19, 24, 46, 60, 101, 124, 206, 250, 378, 462, 684, 812, 1165, 1380, 1927, 2268, 3108, 3606, 4862, 5648, 7474, 8576, 11307, 12886, 16652, 19050, 24420, 27584, 35225, 39604, 49920, 56370, 70540, 78608, 98419, 109666, 135212, 151176, 185875, 205308
Offset: 1

Views

Author

Gus Wiseman, Sep 23 2023

Keywords

Comments

For an integer partition y of n, we call a positive integer k <= n a non-subset-sum iff there is no submultiset of y summing to k.

Examples

			The a(6) = 19 ways, showing each partition and its non-subset-sums:
       (6): 1,2,3,4,5
      (51): 2,3,4
      (42): 1,3,5
     (411): 3
      (33): 1,2,4,5
     (321):
    (3111):
     (222): 1,3,5
    (2211):
   (21111):
  (111111):
		

Crossrefs

Row sums of A046663, strict A365663.
The zero-full complement (subset-sums) is A304792.
The strict case is A365922.
Weighted row-sums of A365923, rank statistic A325799, complement A365658.
A000041 counts integer partitions, strict A000009.
A126796 counts complete partitions, ranks A325781, strict A188431.
A365543 counts partitions with a submultiset summing to k, strict A365661.
A365924 counts incomplete partitions, ranks A365830, strict A365831.

Programs

  • Mathematica
    Table[Total[Length[Complement[Range[n],Total/@Subsets[#]]]&/@IntegerPartitions[n]],{n,10}]
  • Python
    # uses A304792_T
    from sympy import npartitions
    def A365918(n): return (n+1)*npartitions(n)-A304792_T(n,n,(0,),1) # Chai Wah Wu, Sep 25 2023

Formula

a(n) = (n+1)*A000041(n) - A304792(n).

Extensions

a(21)-a(45) from Chai Wah Wu, Sep 25 2023

A365923 Triangle read by rows where T(n,k) is the number of integer partitions of n with exactly k distinct non-subset-sums.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 2, 0, 1, 0, 2, 1, 1, 1, 0, 4, 0, 2, 0, 1, 0, 5, 1, 0, 3, 1, 1, 0, 8, 0, 3, 0, 3, 0, 1, 0, 10, 2, 1, 2, 2, 3, 1, 1, 0, 16, 0, 5, 0, 3, 0, 5, 0, 1, 0, 20, 2, 2, 4, 2, 6, 0, 4, 1, 1, 0, 31, 0, 6, 0, 8, 0, 5, 0, 5, 0, 1, 0, 39, 4, 4, 4, 1, 6, 6, 3, 2, 6, 1, 1, 0
Offset: 0

Views

Author

Gus Wiseman, Sep 24 2023

Keywords

Comments

For an integer partition y of n, we call a positive integer k <= n a non-subset-sum iff there is no submultiset of y summing to k.

Examples

			The partition (4,2) has subset-sums {2,4,6} and non-subset-sums {1,3,5} so is counted under T(6,3).
Triangle begins:
   1
   1  0
   1  1  0
   2  0  1  0
   2  1  1  1  0
   4  0  2  0  1  0
   5  1  0  3  1  1  0
   8  0  3  0  3  0  1  0
  10  2  1  2  2  3  1  1  0
  16  0  5  0  3  0  5  0  1  0
  20  2  2  4  2  6  0  4  1  1  0
  31  0  6  0  8  0  5  0  5  0  1  0
  39  4  4  4  1  6  6  3  2  6  1  1  0
  55  0 13  0  8  0 12  0  6  0  6  0  1  0
  71  5  8  7  3  5  3 16  3  6  0  6  1  1  0
Row n = 6 counts the following partitions:
  (321)     (411)  .  (51)   (33)  (6)  .
  (3111)              (42)
  (2211)              (222)
  (21111)
  (111111)
		

Crossrefs

Row sums are A000041.
The rank statistic counted by this triangle is A325799.
The strict case is A365545, weighted row sums A365922.
The complement (positive subset-sum) is A365658.
Weighted row sums are A365918, for positive subset-sums A304792.
A046663 counts partitions w/o a submultiset summing to k, strict A365663.
A126796 counts complete partitions, ranks A325781, strict A188431.
A364350 counts combination-free strict partitions, complement A364839.
A365543 counts partitions with a submultiset summing to k, strict A365661.
A365924 counts incomplete partitions, ranks A365830, strict A365831.

Programs

  • Mathematica
    Table[Length[Select[IntegerPartitions[n], Length[Complement[Range[n], Total/@Subsets[#]]]==k&]], {n,0,10}, {k,0,n}]

A365922 Number of non-subset-sums of strict integer partitions of n.

Original entry on oeis.org

0, 1, 2, 4, 8, 11, 18, 25, 38, 51, 70, 93, 122, 159, 206, 263, 328, 420, 514, 645, 776, 967, 1154, 1413, 1686, 2042, 2414, 2890, 3394, 4062, 4732, 5598, 6494, 7652, 8836, 10329, 11884, 13833, 15830, 18376, 20936, 24131, 27476, 31547, 35780, 40966, 46292, 52737
Offset: 1

Views

Author

Gus Wiseman, Sep 23 2023

Keywords

Comments

For an integer partition y of n, we call a positive integer k <= n a non-subset-sum iff there is no submultiset of y summing to k.

Examples

			The a(6) = 11 ways, showing each strict partition and its non-subset-sums:
    (6): 1,2,3,4,5
   (51): 2,3,4
   (42): 1,3,5
  (321):
		

Crossrefs

The complement (positive subset-sums) is A284640, non-strict A276024.
Weighted row sums of A365545, non-strict A365923.
Row sums of A365663, non-strict A046663.
The non-strict version is A365918.
The zero-full complement (subset-sums) is A365925, non-strict A304792.
A000041 counts integer partitions, strict A000009.
A126796 counts complete partitions, ranks A325781, strict A188431.
A364350 counts combination-free strict partitions, complement A364839.
A365543 counts partitions with a submultiset summing to k.
A365661 counts strict partitions w/ a subset summing to k.
A365924 counts incomplete partitions, ranks A365830, strict A365831.

Programs

  • Mathematica
    Table[Total[Length[Complement[Range[n], Total/@Subsets[#]]]& /@ Select[IntegerPartitions[n], UnsameQ@@#&]],{n,30}]

A366127 Number of finite incomplete multisets of positive integers with greatest non-subset-sum n.

Original entry on oeis.org

1, 2, 4, 6, 11, 15, 25, 35, 53, 72, 108
Offset: 1

Views

Author

Gus Wiseman, Sep 30 2023

Keywords

Comments

A non-subset-sum of a multiset of positive integers summing to n is an element of {1..n} that is not the sum of any submultiset. A multiset is incomplete if it has at least one non-subset-sum.

Examples

			The non-subset-sums of y = {2,2,3} are {1,6}, with maximum 6, so y is counted under a(6).
The a(1) = 1 through a(6) = 15 multisets:
  {2}  {3}    {4}      {5}        {6}          {7}
       {1,3}  {1,4}    {1,5}      {1,6}        {1,7}
              {2,2}    {2,3}      {2,4}        {2,5}
              {1,1,4}  {1,1,5}    {3,3}        {3,4}
                       {1,2,5}    {1,1,6}      {1,1,7}
                       {1,1,1,5}  {1,2,6}      {1,2,7}
                                  {1,3,3}      {1,3,4}
                                  {2,2,2}      {2,2,3}
                                  {1,1,1,6}    {1,1,1,7}
                                  {1,1,2,6}    {1,1,2,7}
                                  {1,1,1,1,6}  {1,1,3,7}
                                               {1,2,2,7}
                                               {1,1,1,1,7}
                                               {1,1,1,2,7}
                                               {1,1,1,1,1,7}
		

Crossrefs

For least instead of greatest we have A126796, ranks A325781, strict A188431.
These multisets have ranks A365830.
Counts appearances of n in the rank statistic A365920.
Column sums of A365921.
These multisets counted by sum are A365924, strict A365831.
The strict case is A366129.
A000041 counts integer partitions, strict A000009.
A046663 counts partitions without a submultiset summing k, strict A365663.
A325799 counts non-subset-sums of prime indices.
A364350 counts combination-free strict partitions, complement A364839.
A365543 counts partitions with a submultiset summing to k.
A365661 counts strict partitions w/ a subset summing to k.
A365918 counts non-subset-sums of partitions.
A365923 counts partitions by non-subset sums, strict A365545.

Programs

  • Mathematica
    prix[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
    nmz[y_]:=Complement[Range[Total[y]],Total/@Subsets[y]];
    Table[Length[Select[Join@@IntegerPartitions/@Range[n,2*n],Max@@nmz[#]==n&]],{n,5}]
Showing 1-6 of 6 results.