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.

A209673 a(n) = count of monomials, of degree k=n, in the Schur symmetric polynomials s(mu,k) summed over all partitions mu of n.

Original entry on oeis.org

1, 1, 4, 19, 116, 751, 5552, 43219, 366088, 3245311, 30569012, 299662672, 3079276708, 32773002718, 362512238272, 4136737592323, 48773665308176, 591313968267151, 7375591544495636, 94340754464144215, 1237506718985945656, 16608519982801477908, 228013066931927465872
Offset: 0

Views

Author

Wouter Meeussen, Mar 11 2012

Keywords

Comments

Main diagonal of triangle A191714.
a(n) is also the number of semistandard Young tableaux of size and maximal entry n. - Christian Stump, Oct 09 2015

Crossrefs

Programs

  • Mathematica
    (* see A191714 *)
    Tr /@ Table[(stanley[#, l] & /@ Partitions[l]), {l, 11}]
    (* or *)
    Table[SeriesCoefficient[1/((1-x)^(n*(n+1)/2) * (1+x)^(n*(n-1)/2)), {x, 0, n}], {n, 0, 25}] (* Vaclav Kotesovec, Aug 06 2025 *)

Extensions

a(12)-a(22) from Alois P. Heinz, Mar 11 2012
Typo in Mathematica program fixed by Vaclav Kotesovec, Mar 19 2015

A209669 T(n,k) = count of degree k monomials in the elementary symmetric polynomials e(mu,k) summed over all partitions mu of n.

Original entry on oeis.org

1, 1, 5, 1, 10, 37, 1, 21, 120, 405, 1, 42, 363, 1644, 5251, 1, 85, 1117, 6814, 27405, 84893, 1, 170, 3360, 27404, 138085, 514248, 1556535, 1, 341, 10164, 111045, 701960, 3145848, 11133493, 33175957, 1, 682, 30520, 445132, 3521405, 18956548, 78337448
Offset: 1

Views

Author

Wouter Meeussen, Mar 11 2012

Keywords

Comments

T(n,2) = A000975(n+1) because only partitions into parts of 1 and 2 contribute, so that T(n,2) = Sum_{k=0..floor(n/2)} 2^(n-2k). - Peter J. Taylor, Mar 01 2017

Examples

			Table starts as
1;
1,  5;
1, 10,  37;
1, 21, 120,  405;
1, 42, 363, 1644, 5251;
...
For n = 2, k = 2 the partitions of n are 2 and 1+1, which correspond respectively to (xy) contributing 1 and (x+y)*(x+y) contributing 4 for a total of 5. - _Peter J. Taylor_, Mar 01 2017
		

Crossrefs

Row sums are A209670, main diagonal is A209671.
Second column is A000975 offset by 1. - Peter J. Taylor, Mar 01 2017

Programs

  • Mathematica
    e[n_, v_] := Tr[Times @@@ Select[Subsets[Table[Subscript[x, j], {j, v}]], Length[#] == n &]]; e[par_?PartitionQ, v_] := Times @@ (e[#, v] & /@ par); Table[Tr[(e[#, k] & /@ Partitions[l]) /. Subscript[x, _] -> 1], {l, 10}, {k, l}]
  • Python
    # See Taylor link

Formula

T(n,k) = Sum_{lambda} Product_{i} binomial(k, lambda_i) where the sum is over partitions of n. - Peter J. Taylor, Mar 01 2017

A209667 a(n) = count of monomials, of degrees k=0 to n, in the complete homogeneous symmetric polynomials h(mu,k) summed over all partitions mu of n.

Original entry on oeis.org

1, 1, 9, 76, 902, 11635, 192205, 3450337, 73128340, 1696862300, 44414258862, 1264163699189, 39640715859359, 1340191402045395, 49097854149726795, 1924982506686743639, 80831323253459088871, 3607487926962810556542, 170964537623741430399076
Offset: 0

Views

Author

Wouter Meeussen, Mar 11 2012

Keywords

Crossrefs

Programs

  • Maple
    b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
          add(b(n-i*j, i-1, k)*binomial(i+k-1, k-1)^j, j=0..n/i)))
        end:
    a:= n-> add(b(n$2, k), k=0..n):
    seq(a(n), n=0..20);  # Alois P. Heinz, Mar 04 2016
  • Mathematica
    h[n_, v_] := Tr@ Apply[Times, Table[Subscript[x, j], {j, v}]^# & /@ Compositions[n, v], {1}]; h[par_?PartitionQ, v_] := Times @@ (h[#, v] & /@ par); Tr/@ Table[Tr[(h[#, k] & /@ Partitions[l]) /. Subscript[x, _] -> 1], {l, 10}, {k, l}]

Formula

Row sums of table A209666.

Extensions

a(0), a(11)-a(18) from Alois P. Heinz, Mar 04 2016
Showing 1-3 of 3 results.