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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A323437 Number of semistandard Young tableaux whose entries are the prime indices of n.

Original entry on oeis.org

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

Views

Author

Gus Wiseman, Jan 15 2019

Keywords

Comments

Number of ways to fill a Young diagram with the prime indices of n such that all rows are weakly increasing and all columns are strictly increasing.
A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.
Is this a duplicate of A339887? - R. J. Mathar, Feb 03 2021

Examples

			The a(60) = 5 tableaux:
  1123
.
  11   112   113
  23   3     2
.
  11
  2
  3
		

Crossrefs

Programs

  • Mathematica
    primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
    facs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[facs[n/d],Min@@#>=d&]],{d,Rest[Divisors[n]]}]];
    ptnplane[n_]:=Union[Map[primeMS,Join@@Permutations/@facs[n],{2}]];
    Table[Length[Select[ptnplane[y],And[And@@Less@@@#,And@@(LessEqual@@@Transpose[PadRight[#]/.(0->Infinity)])]&]],{y,100}]

Formula

Sum_{A056239(n) = k} a(k) = A003293(n).

A138177 Triangle T(n,k) read by rows: number of k X k symmetric matrices with nonnegative integer entries and without zero rows or columns such that sum of all entries is equal to n, n>=1, 1<=k<=n.

Original entry on oeis.org

1, 1, 2, 1, 4, 4, 1, 7, 15, 10, 1, 10, 36, 52, 26, 1, 14, 74, 176, 190, 76, 1, 18, 132, 460, 810, 696, 232, 1, 23, 222, 1060, 2705, 3756, 2674, 764, 1, 28, 347, 2180, 7565, 15106, 17262, 10480, 2620, 1, 34, 525, 4204, 19013, 51162, 83440, 80816, 42732, 9496, 1, 40
Offset: 1

Views

Author

Vladeta Jovovic, Mar 03 2008

Keywords

Comments

See the Brualdi/Ma reference for the connection to A161126. - Joerg Arndt, Nov 02 2014
T(n,k) is also the number of semistandard Young tableaux of size n whose entries span the interval 1..k. See also Gus Wiseman's comment in A138178. The T(4,2) = 7 semi-standard Young tableaux of size 4 spanning the interval 1..2 are:
11 122 112 111 1222 1122 1112
22 2 2 2 . - Jacob Post, Jun 15 2018

Examples

			Triangle T(n,k) begins:
  1;
  1,  2;
  1,  4,   4;
  1,  7,  15,   10;
  1, 10,  36,   52,   26;
  1, 14,  74,  176,  190,   76;
  1, 18, 132,  460,  810,  696,  232;
  1, 23, 222, 1060, 2705, 3756, 2674, 764;
  ...
		

Crossrefs

Cf. (row sums) A138178, A135589, A135588, A161126, A210391.
Main diagonal gives A000085. - Alois P. Heinz, Apr 06 2015
T(2n,n) gives A266305.
T(n^2,n) gives A268309.

Programs

  • Maple
    gf:= k-> 1/((1-x)^k*(1-x^2)^(k*(k-1)/2)):
    A:= (n, k)-> coeff(series(gf(k), x, n+1), x, n):
    T:= (n, k)-> add(A(n, k-i)*(-1)^i*binomial(k, i), i=0..k):
    seq(seq(T(n, k), k=1..n), n=1..12);  # Alois P. Heinz, Apr 06 2015
  • Mathematica
    gf[k_] := 1/((1-x)^k*(1-x^2)^(k*(k-1)/2)); A[n_, k_] := Coefficient[ Series [gf[k], {x, 0, n+1}], x, n]; T[n_, k_] := Sum[(-1)^j*Binomial[k, j]*A[n, k-j], {j, 0, k}]; Table[T[n, k], {n, 1, 12}, {k, 1, n}] // Flatten (* Jean-François Alcover, Jan 31 2016, after Alois P. Heinz *)

Formula

T(n,k) = Sum_{i=0..k} (-1)^i * binomial(k,i) * A210391(n,k-i). - Alois P. Heinz, Apr 06 2015

A299699 Number of rim-hook (or border-strip) tableaux of size n.

Original entry on oeis.org

1, 4, 13, 50, 179, 744, 2975, 13020, 57215, 265172, 1245355
Offset: 1

Views

Author

Gus Wiseman, Feb 16 2018

Keywords

Comments

A rim-hook tableau is a generalized Young tableau in which all columns and rows are weakly decreasing and all regions are connected border-strips.

Examples

			The a(3) = 13 tableaux:
3   2   2   1   3 2   3 1   2 2   2 1   1 1   3 2 1   2 2 1   2 1 1   1 1 1
2   2   1   1   1     2     1     2     1
1   1   1   1
		

References

  • Richard P. Stanley, Enumerative Combinatorics Volume 2, Cambridge University Press, 1999, Chapter 7.17.

Crossrefs

A300124 Number of ways to tile the diagram of an integer partition of n using connected skew partitions.

Original entry on oeis.org

1, 4, 12, 42, 120, 416, 1184, 3888
Offset: 1

Views

Author

Gus Wiseman, Feb 25 2018

Keywords

Comments

The diagram of a connected skew partition is required to be connected as a polyomino but can have empty rows or columns.

Crossrefs

A323582 Number of generalized Young tableaux with constant rows, weakly increasing columns, and entries summing to n.

Original entry on oeis.org

1, 1, 3, 5, 11, 16, 33, 47, 85, 126, 208, 299, 486, 685, 1050, 1496, 2221, 3097, 4523, 6239, 8901, 12219, 17093, 23202, 32120, 43200, 58899, 78761, 106210, 140786, 188192, 247689, 327965, 429183, 563592, 732730, 955851, 1235370, 1600205, 2057743, 2649254
Offset: 0

Views

Author

Gus Wiseman, Jan 19 2019

Keywords

Comments

For strictly increasing columns, see A100883.

Examples

			The a(5) = 16 tableaux:
  5   1 1 1 1 1
.
  1   2    1 1   1 1 1   1 1 1   1 1 1 1
  4   3    3     2       1 1     1
.
  1   1    1 1   1 1     1 1 1
  1   2    1     1 1     1
  3   2    2     1       1
.
  1   1 1
  1   1
  1   1
  2   1
.
  1
  1
  1
  1
  1
		

Crossrefs

Programs

  • Mathematica
    comps[q_]:=Table[Table[Take[q,{Total[Take[c,i-1]]+1,Total[Take[c,i]]}],{i,Length[c]}],{c,Join@@Permutations/@IntegerPartitions[Length[q]]}];
    Table[Sum[Length[Select[comps[ptn],And@@SameQ@@@#&&GreaterEqual@@Length/@#&]],{ptn,Sort/@IntegerPartitions[n]}],{n,10}]

Extensions

a(21)-a(40) from Seiichi Manyama, Aug 20 2020

A300118 Number of skew partitions whose quotient diagram is connected and whose numerator is the integer partition with Heinz number n.

Original entry on oeis.org

1, 2, 3, 3, 4, 4, 5, 4, 6, 5, 6, 5, 7, 6, 7, 5, 8, 7, 9, 6, 8, 7, 10, 6, 10, 8, 10, 7, 11, 8, 12, 6, 9, 9, 11, 8, 13, 10, 10, 7, 14, 9, 15, 8, 11, 11, 16, 7, 15, 11, 11, 9, 17, 11, 12, 8, 12, 12, 18, 9, 19, 13, 12, 7, 13, 10, 20, 10, 13, 12, 21, 9, 22, 14, 15, 11
Offset: 1

Views

Author

Gus Wiseman, Feb 25 2018

Keywords

Comments

The diagram of a connected skew partition is required to be connected as a polyomino but can have empty rows or columns.

Examples

			The a(15) = 7 denominators are (), (1), (11), (22), (3), (31), (32) with diagrams:
o o o   . o o   . o o   . . o   . . .   . . .   o o o
o o     o o     . o     . .     o o     . o     o o
Missing are the two disconnected skew partitions:
. . o   . . o
o o     . o
		

Crossrefs

Programs

  • Mathematica
    primeMS[n_]:=If[n===1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
    undcon[y_]:=Select[Tuples[Range[0,#]&/@y],Function[v,GreaterEqual@@v&&With[{r=Select[Range[Length[y]],y[[#]]=!=v[[#]]&]},Or[Length[r]<=1,And@@Table[v[[i]]
    				

A321406 Number of non-isomorphic self-dual set systems of weight n with no singletons.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 1, 1, 1, 2, 4
Offset: 0

Views

Author

Gus Wiseman, Nov 15 2018

Keywords

Comments

Also the number of 0-1 symmetric matrices up to row and column permutations with sum of elements equal to n and no zero rows or columns, in which the rows are all different and none sums to 1.
The dual of a multiset partition has, for each vertex, one part consisting of the indices (or positions) of the parts containing that vertex, counted with multiplicity. For example, the dual of {{1,2},{2,2}} is {{1},{1,2,2}}.
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.

Examples

			Non-isomorphic representatives of the a(6) = 1 through a(10) = 4 set systems:
   6: {{1,2},{1,3},{2,3}}
   7: {{1,3},{2,3},{1,2,3}}
   8: {{1,2},{1,3},{2,4},{3,4}}
   9: {{1,2},{1,3},{1,4},{2,3,4}}
   9: {{1,2},{1,4},{3,4},{2,3,4}}
  10: {{1,2},{2,4},{1,3,4},{2,3,4}}
  10: {{1,3},{2,4},{1,3,4},{2,3,4}}
  10: {{1,4},{2,4},{3,4},{1,2,3,4}}
  10: {{1,2},{1,3},{2,4},{3,5},{4,5}}
		

Crossrefs

A321411 Number of non-isomorphic self-dual multiset partitions of weight n with no singletons, with aperiodic parts whose sizes are relatively prime.

Original entry on oeis.org

1, 0, 0, 0, 0, 1, 0, 4, 6, 16, 25
Offset: 0

Views

Author

Gus Wiseman, Nov 16 2018

Keywords

Comments

A multiset is aperiodic if its multiplicities are relatively prime.
Also the number of nonnegative integer symmetric matrices up to row and column permutations with sum of elements equal to n and no zero rows or columns, with relatively prime row sums (or column sums) and no row or column having a common divisor > 1 or summing to 1.
The dual of a multiset partition has, for each vertex, one part consisting of the indices (or positions) of the parts containing that vertex, counted with multiplicity. For example, the dual of {{1,2},{2,2}} is {{1},{1,2,2}}.
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.

Examples

			Non-isomorphic representatives of the a(5) = 1 through a(9) = 16 multiset partitions:
  {{12}{122}}  {{112}{1222}}    {{112}{12222}}    {{1112}{11222}}
               {{12}{12222}}    {{122}{11222}}    {{1112}{12222}}
               {{12}{13}{233}}  {{12}{123}{233}}  {{12}{1222222}}
               {{13}{23}{123}}  {{13}{112}{233}}  {{12}{123}{2333}}
                                {{13}{122}{233}}  {{12}{13}{23333}}
                                {{23}{123}{123}}  {{12}{223}{1233}}
                                                  {{13}{112}{2333}}
                                                  {{13}{223}{1233}}
                                                  {{13}{23}{12333}}
                                                  {{23}{122}{1233}}
                                                  {{23}{123}{1233}}
                                                  {{12}{12}{34}{234}}
                                                  {{12}{12}{34}{344}}
                                                  {{12}{13}{14}{234}}
                                                  {{12}{13}{24}{344}}
                                                  {{12}{14}{34}{234}}
		

Crossrefs

A323450 Number of ways to fill a Young diagram with positive integers summing to n such that all rows and columns are weakly increasing.

Original entry on oeis.org

1, 1, 3, 6, 14, 26, 56, 103, 203, 374, 702, 1262, 2306, 4078, 7242, 12628, 21988, 37756, 64682, 109606, 185082, 309958, 516932, 856221, 1412461, 2316416, 3783552
Offset: 0

Views

Author

Gus Wiseman, Jan 16 2019

Keywords

Comments

A generalized Young tableau of shape y is an array obtained by replacing the dots in the Ferrers diagram of y with positive integers.

Examples

			The a(4) = 14 generalized Young tableaux:
  4   1 3   2 2   1 1 2   1 1 1 1
.
  1   2   1 1   1 2   1 1   1 1 1
  3   2   2     1     1 1   1
.
  1   1 1
  1   1
  2   1
.
  1
  1
  1
  1
The a(5) = 26 generalized Young tableaux:
  5   1 4   2 3   1 1 3   1 2 2   1 1 1 2   1 1 1 1 1
.
  1   2   1 1   1 3   1 2   1 1   1 1 1   1 1 2   1 1 1   1 1 1 1
  4   3   3     1     2     1 2   2       1       1 1     1
.
  1   1   1 1   1 2   1 1   1 1 1
  1   2   1     1     1 1   1
  3   2   2     1     1     1
.
  1   1 1
  1   1
  1   1
  2   1
.
  1
  1
  1
  1
  1
		

Crossrefs

Programs

  • Mathematica
    primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
    facs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[facs[n/d],Min@@#>=d&]],{d,Rest[Divisors[n]]}]];
    ptnplane[n_]:=Union[Map[primeMS,Join@@Permutations/@facs[n],{2}]];
    Table[Sum[Length[Select[ptnplane[Times@@Prime/@y],And@@(LessEqual@@@Transpose[PadRight[#]/.(0->Infinity)])&]],{y,IntegerPartitions[n]}],{n,10}]

Extensions

a(16)-a(26) from Seiichi Manyama, Aug 19 2020

A299966 Number of normal generalized Young tableaux, of shape the integer partition with Heinz number n, with all rows and columns weakly increasing and all regions non-singleton skew-partitions.

Original entry on oeis.org

1, 0, 1, 1, 1, 1, 2, 1, 3, 3, 3, 3, 5, 5, 5, 2, 8, 5, 13, 6, 13, 10, 21, 5, 11, 18, 11, 14, 34, 15, 55, 3, 26, 33, 23, 13, 89, 59, 54, 14, 144, 38, 233, 28, 31, 105, 377, 10, 47, 31, 106, 57, 610, 23, 60, 32, 206, 185, 987, 38, 1597, 324, 91, 5, 132, 93, 2584, 111
Offset: 1

Views

Author

Gus Wiseman, Feb 22 2018

Keywords

Comments

A generalized Young tableau of shape y is an array obtained by replacing the dots in the Ferrers diagram of y with positive integers. A tableau is normal if its entries span an initial interval of positive integers. The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).

Examples

			The a(25) = 11 tableaux:
1 2 3   1 2 2   1 1 3   1 1 2
1 2 3   1 3 3   2 2 3   2 3 3
.
1 2 2   1 1 2   1 1 2   1 1 2   1 1 1   1 1 1
1 2 2   2 2 2   1 2 2   1 1 2   2 2 2   1 2 2
.
1 1 1
1 1 1
		

References

  • Bruce E. Sagan, The Symmetric Group, Springer-Verlag New York, 2001.

Crossrefs

Programs

  • Mathematica
    primeMS[n_]:=If[n===1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
    undptns[y_]:=DeleteCases[Select[Tuples[Range[0,#]&/@y],OrderedQ[#,GreaterEqual]&],0,{2}];
    eh[y_]:=If[Total[y]=!=1,1,0]+Sum[eh[c],{c,Select[undptns[y],Total[#]>1&&Total[y]-Total[#]>1&]}];
    Table[eh[Reverse[primeMS[n]]],{n,60}]
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