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.

A214043 Count of Laurent monomials (including multiplicities), in the Symplectic Schur symmetric polynomials s(mu, n) summed over all partitions mu of n.

Original entry on oeis.org

2, 15, 134, 1589, 20162, 293580, 4519916, 75850054, 1334978228, 24987138510, 487322528552, 9968005618302, 211338028257280, 4658444968474433, 105985325960653194, 2492041019432287042, 60271996071301852442, 1500054086883728030496
Offset: 1

Views

Author

T. Amdeberhan, Jul 13 2012

Keywords

Examples

			For n = 2, partition = (1, 1), the Symplectic Schur is: x_1*x_2 + x_1/x_2 + x_2/x_1 + 1/(x_1*x_2) + 1. There are five terms here. Partition (2) contributes another ten terms, including the term 1 twice. So a(2) = 5+10 = 15. [Extended by _Andrey Zabolotskiy_, Jan 24 2018]
		

Programs

  • Mathematica
    s[mu_,n_] := Expand[Simplify[Det[Table[x[j]^(mu[[i]]+n-i+1) - x[j]^(-mu[[j]]-n+i-1), {i,n}, {j,n}]] / Det[Table[x[j]^(n-i+1) - x[j]^(-n+i-1), {i,n}, {j,n}]]]];
    Table[Sum[s[PadRight[mu,n], n] /. {x[_]->1}, {mu, IntegerPartitions[n]}], {n, 5}]
    (* Andrey Zabolotskiy, Jan 24 2018 *)